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SUBJECT TO COMPLETION

PRELIMINARY PROSPECTUS SUPPLEMENT DATED JANUARY 21, 2002

The information in this prospectus supplement and the accompanying prospectus is not complete and may be changed. This prospectus supplement and the accompanying prospectus are not an offer to sell these securities and are not soliciting an offer to buy these securities in any state where the offer or sale is not permitted.

PROSPECTUS SUPPLEMENT

(To prospectus dated September 21, 2001)

11,000,000 Shares

Common Stock

        We are an energy and energy solutions provider with our principal operations in the United States, Australia, New Zealand, Canada and Western Europe. We are offering and selling 11,000,000 shares of common stock with this prospectus supplement.

        Our shares are listed on the New York, Pacific and Toronto Stock Exchanges under the symbol "UCU." On January 18, 2002, the last reported sale price of our common stock on the New York Stock Exchange was $25.34 per share.

Investing in the common stock involves risks that are described in the "Risk Factors" section beginning on page S-10 of this prospectus supplement.

	Per Share	Total
Public offering price	$	$
Underwriting discount	$	$
Proceeds, before expenses, to UtiliCorp United Inc.	$	$

        The underwriters may also purchase up to an additional 1,500,000 shares from us at the public offering price, less the underwriting discount, within 30 days from the date of this prospectus supplement to cover over-allotments.

        Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or the prospectus to which it relates is truthful or complete. Any representation to the contrary is a criminal offense.

        The shares will be ready for delivery on or about January     , 2002.

Joint Book-Running Managers

Salomon Smith Barney UBS Warburg

Co-Managers

Deutsche Banc Alex. Brown

Credit Lyonnais Securities (USA) Inc.

The date of this prospectus supplement is January      , 2002.

TABLE OF CONTENTS

Prospectus Supplement

	Page
Summary	S-1
Risk Factors	S-10
Forward Looking Statements	S-12
Use of Proceeds	S-14
Price Range of Common Stock and Dividends	S-14
Capitalization	S-15
Underwriting	S-16
Legal Matters	S-18
Prospectus
About This Prospectus	2
Where You Can Find More Information	3
The Company	3
Use of Proceeds	3
Ratio of Earnings to Fixed Charges	4
Description of Common Stock	4
Description of Senior Notes	8
Plan of Distribution	12
Experts	13

You should rely only on the information contained or incorporated by reference in this prospectus supplement and the accompanying prospectus. We have not, and the underwriters have not, authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. We are not, and the underwriters are not, making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information appearing in this prospectus supplement, the accompanying prospectus and the documents incorporated by reference is accurate only as of their respective dates. Our business, financial condition, results of operations and prospects may have changed since those dates.

        Unless otherwise indicated or unless the context requires otherwise, all references in this prospectus supplement to "UtiliCorp," "we," "our," "us," or similar references mean UtiliCorp United Inc. and its subsidiaries. All references to "EBIT" in this prospectus supplement refer to earnings before interest and taxes. EBIT is presented as an additional measure of our ability to service our debt and to fund expenditures. It is not a measure of operating results, but is derived from our consolidated financial statements. It should not be considered in isolation or as a substitute for a measure of performance prepared in accordance with generally accepted accounting principles, or "GAAP," in the United States and is not indicative of operating income or cash flow from operations as determined under GAAP. In addition, EBIT may not be comparable with other companies' EBIT due to different ways in which EBIT may be defined.

SUMMARY

This summary highlights information contained elsewhere in this prospectus supplement and the accompanying prospectus. This summary may not contain all of the information that may be important to you. You should read the entire prospectus supplement and the accompanying prospectus carefully before making an investment decision.

Our Company

        We are a multinational energy and energy solutions provider headquartered in Kansas City, Missouri. We currently operate regulated networks and/or merchant businesses on three continents. Our businesses are organized into two groups consisting of our Global Networks Group and Energy Merchant Group.

UtiliCorp Organizational Structure

(1)

Total excludes corporate and other assets of $344.5 million

(2)

Wholesale Services includes $3.8 billion of current assets

(3)

Excludes gain on sale of Aquila shares by UCU of $110.8 million, minority interest in income of Aquila of $(23.9) million and corporate and other expenses of $0.7 million

S-1

Global Networks Group

        Our Global Networks Group includes our Networks Group, consisting of our domestic and international regulated electric and gas operations, and our Services Group. In the United States, we provide gas and/or electricity to approximately 1.3 million customers in seven Midwestern states: Colorado, Iowa, Kansas, Michigan, Minnesota, Missouri and Nebraska.

        The following table summarizes sales, volumes and customers for our domestic electric network utility generation, transmission and distribution businesses.

	Nine Months Ended September 30,										3 Year Compounded Annual Growth Rate
					Years Ended December 31,
	2001		2000		2000		1999		1998
Sales (in millions)	$	606.9	$	540.4	$	717.6	$	675.4	$	616.6	8.8	%
Volumes (Megawatt Hours in thousands)		10,118		9,160		12,173		12,043		12,443	2.8	%
Customers at Period End		430,239		345,369		408,493		349,306		373,405	3.8	%

        The following table summarizes sales, volumes and customers for our domestic gas network businesses.

	Nine Months Ended September 30,										3 Year Compounded Annual Growth Rate
					Years Ended December 31,
	2001		2000		2000		1999		1998
Sales (in millions)	$	768.8	$	466.7	$	826.5	$	638.2	$	622.5	2.5	%
Volumes (Million Cubic Feet in thousands)		160,100		172,000		241,708		247,831		250,010	(5.6	)%
Customers at Period End		853,552		839,500		862,716		831,171		848,049	1.4	%

        Internationally, we own interests in electric and natural gas utilities and broadband networks in Australia and New Zealand which serve approximately 2.2 million customers and we also provide electric distribution services to approximately 500,000 customers in Canada. For the nine months ended September 30, 2001, our Networks Group had sales of approximately $2.1 billion, compared to sales of approximately $1.6 billion during the same period of the prior year, and EBIT of $253 million, compared to EBIT of $271 million during the same period of the prior year.

        Our Global Networks Group also includes our Services Group, consisting primarily of (a) our approximately 38% interest in Quanta Services, Inc., a publicly traded company (NYSE:PWR) that is a leading provider of specialized contracting services to utilities, telecommunications and cable television companies, and government agencies and (b) our domestic broadband communications business. For the nine months ended September 30, 2001, our Services Group had sales of $11 million and a loss before interest and taxes of $7 million, compared to EBIT of $26 million during the same period of the prior year.

S-2

Energy Merchant Group

        Our Energy Merchant Group consists primarily of our 100% ownership interest in Aquila, Inc., which markets and trades wholesale natural gas, electricity and other commodities, and deals in a wide range of energy-related financial and risk management products and services in North America and Western Europe. Aquila also owns, operates and contractually controls electric power generation assets, natural gas gathering, transportation, processing and storage assets, and a coal blending, storage and handling facility. For the nine months ended September 30, 2001, the Energy Merchant Group had sales of approximately $29.7 billion, compared to sales of approximately $16.8 billion during the same period of the prior year, and EBIT of $418 million (including a $111 million pre-tax gain on the sale of Aquila shares by UtiliCorp in Aquila's initial public offering) compared to EBIT of $105 million during the same period of the prior year. According to statistics published in Natural Gas Week, as of September 20, 2001, Aquila was the sixth largest marketer of natural gas and eighth largest marketer of power in North America.

        The following table summarizes Aquila's recent volumes.

	Nine Months Ended September 30,		Years Ended December 31,
	2001	2000	2000	1999	1998
Physical gas volumes marketed per day (Bcf/d)	12.7	11.6	12.0	10.5	9.0
Electricity marketing volumes (MMWhs)	220	129	189.9	236.5	121.2
Gas throughput volumes per day (Mcf/d)	386	461	449	548	475

Bcf/d = one billion cubic feet per day
MMWhs = one million megawatt hours
Mcf/d = one million cubic feet per day

Our Strategy

        Our overall strategy is to be a premier energy and energy solutions provider through the growth and management of network assets and our energy merchant business. We also intend to continue our "invest, optimize and monetize" philosophy in which we seek to identify and invest in attractive assets and optimize the structure, operation and performance of our existing assets and our new investments. We then selectively monetize the value we have created in these assets and reinvest that capital in other investments. We believe this strategy will enable us to enhance shareholder value, particularly with the recombination of the financial strength of UtiliCorp with the growth opportunities of Aquila. With its larger asset base, higher earnings and cash flow potential, the combined company will have more efficient access to capital to execute our vision.

        In connection with its decision to propose a recombination of UtiliCorp and Aquila (as more fully discussed in "Recent Developments" on page S-4), our board decided that a combined company would be best served by embracing Aquila's energy merchant strategy, and utilizing the financial strength, asset base, earnings and cash flow, and access to capital of the combined company to support this strategy. As a part of this strategy, we expect to pursue acquisitions and investments that leverage our commodity services capability and allow us to continue to further develop risk management products for our clients. We also intend to monetize portions of our global networks business over time with the goal of shifting capital from our lower-growth networks assets to higher-growth opportunities, while at the same time retaining a sufficient portion of our networks business to maintain stable cash flows. As part of our commitment to further broaden our strategy to focus on the energy merchant business, our board authorized us to change our corporate name to Aquila, Inc., which we expect to finalize in February 2002.

S-3

        Our Global Networks Group is expected to continue to grow primarily through international mergers and acquisitions, such as the Midlands acquisition described below. Historically, we have attempted to mitigate risks associated with international investments by limiting our capital investment to the amount required to gain operating control of assets and by focusing on countries with stable political and economic environments. In order to optimize the value of our investments, we generally seek to finance our international investments with local currencies, and, when feasible, we make these investments through joint ventures with local strategic financial partners. This structure allows us to leverage our operating skills with our partners' financial resources and local political knowledge.

        Our Energy Merchant Group intends to selectively pursue profitable opportunities created by the unbundling and restructuring initiatives in the wholesale commodity markets, including the natural gas and power markets. We will continue to capitalize on opportunities in the US and Europe and trading in other commodities by leveraging our knowledge base from our active participation in the natural gas and power markets. We believe that the exit of Enron Corporation from the energy merchant sector has created an important opportunity for us to expand our client base for energy-related financial and risk management products and services.

Recent Developments

        Aquila IPO and Recombination.    In April 2001, Aquila completed an initial public offering (or IPO) in which it sold 14,225,000 shares, and we sold 5,750,000 shares, of Aquila's Class A common stock to the public at $24 per share. Aquila received net proceeds of approximately $316 million and we received net proceeds of approximately $130 million from the IPO. Since the IPO, we have held all of Aquila's Class B common stock, representing approximately 80% of all of the outstanding shares of Aquila's Class A and Class B common stock combined and approximately 98% of the combined voting power of Aquila's voting stock.

        In connection with Aquila's IPO, we announced that it was then our current intention to complete a spin-off of our remaining interest in Aquila within 12 months of the IPO. We indicated, however, that we would not complete the spin-off if our board of directors determined that doing so was no longer in the best interests of UtiliCorp and its stockholders. The IPO initially achieved our objectives and resulted in the realization of significant value. It clarified, highlighted and focused Aquila's strategy internally and with investors. Despite Aquila's significant earnings growth and the value created, the recent downturn in general economic conditions and the energy merchant sector since Aquila's IPO ultimately caused us to cancel our plan to spin-off Aquila as an independent public company.

        On January 4, 2002, we completed an offer to the public shareholders of Aquila to exchange each share of Aquila's common stock held by them for 0.6896 of a share of our common stock. The exchange offer was promptly followed by a short-form merger of Aquila with a subsidiary of UtiliCorp pursuant to which each share of Aquila held by the public (other than by persons who properly perfect appraisal rights under Delaware law) was exchanged for 0.6896 of a share of our common stock.

        Although there was a consolidated lawsuit filed in connection with the Aquila recombination, the plaintiff's initial claims for equitable relief have been denied by the courts. We do not believe that the pending litigation will have an outcome materially adverse to us.

        Pending Acquisition of Midlands.    On November 7, 2001, we entered into an acquisition agreement with EI UK Holdings, Inc., a wholly owned subsidiary of FirstEnergy Corp., under which we agreed to purchase the stock of Avon Energy Partners Holdings, a wholly owned subsidiary of EI UK Holdings, Inc. that serves as the holding company for Midlands Electricity plc. Midlands Electricity owns the fourth-largest regional electricity provider in the United Kingdom, serving 2.3 million network customers. The purchase price for this acquisition is $362 million, plus the assumption of approximately $1.7 billion of debt that would be non-recourse to us. If consummated, we would expect to account for

S-4

this acquisition using the equity method of accounting. Although we have received the necessary regulatory approvals, the Missouri Public Service Commission's approval is conditioned upon the participation of a financial partner that would pay half of the purchase price, as represented in our application for approval. We have not yet finalized an agreement with our proposed financial partner. We are currently evaluating the financial effect of Enron's bankruptcy on the value of power purchase contracts that Enron has in place with Midlands Electricity. Under the acquisition agreement, if the transaction is not completed by February 25, 2002, either party may terminate the acquisition.

        Potential Accounting Consolidation with Quanta.    We intend, subject to availability, price and other considerations, to increase, through open market purchases, our percentage ownership in Quanta to a percentage that will enable us to reflect Quanta's assets, liabilities and financial results in our consolidated financial statements. To satisfy the accounting requirements necessary to allow us to consolidate Quanta's financial statements with our financial statements, we must own a number of Quanta shares sufficient to give us the ability (or otherwise through the control of Quanta's board have the ability) to control the policies and direction of Quanta's management. We do not currently own a sufficient number of Quanta shares or control enough board seats to meet this requirement. We are presently arbitrating a dispute with Quanta regarding our right to acquire shares of Quanta. While the cost basis in our Quanta investment is currently above market value, our management is confident in the long term potential of our Quanta investment.

        Enron Bankruptcy.    On December 2, 2001, Enron Corporation filed for bankruptcy under Chapter 11 of the U.S. Bankruptcy Code. As described below under "2001 Earnings and Outlook," we recorded an after-tax reserve in the fourth quarter of approximately $40 million related to credit relationships we had with Enron. Also, as discussed above under "Pending Acquisition of Midlands," a company that we have a contract to acquire has exposure to Enron. The absence of Enron from the energy merchant business has not had a material adverse effect on our trading operations, and we believe it has created opportunities for us to expand our commodity risk management products and services business.

        NiSource Alliance.    On January 14, 2002, Aquila and NiSource Inc. formed an alliance under which the two companies will seek to capitalize on market opportunities and deliver comprehensive energy solutions by leveraging the capabilities and knowledge of the two companies. NiSource is the third-largest natural gas distributor in North America, the second largest holder of gas storage assets in the Appalachian basin, and the largest gas producer in the Appalachian basin. While the details of the alliance are still being developed, the alliance is designed to combine the expertise of the two companies in order to leverage the value of NiSource's asset base with Aquila's extensive merchant capabilities.

        2001 Earnings and Outlook.    On January 21, 2002, we issued a press release announcing that we expect 2001 operating earnings per diluted share of $2.44, after giving effect to the following non-recurring adjustments:

•

An after-tax gain of $59 million, or $.51 per share, related to the initial public offering of Aquila, Inc.



•

An after-tax reserve of approximately $40 million, or $.34 per share, arising from trading and financing transactions involving Enron and its subsidiaries;



•

An after-tax write-off of $9.9 million, or $.09 per share, related to limiting the build-out of our broadband network to only the Kansas City market; and



•

An after-tax write-off of $11.5 million, or $.10 per share, related to asset valuation reserves required at our international businesses.

S-5

        We have revised our near-term capital and operating growth plans to reflect current energy industry and capital markets conditions. The revision in our growth plans and dilution from this offering led us to revise our 2002 earnings per share target growth rate to 10 percent and our long-term earnings per share target growth rate to a 10-15 percent range.

        A detailed description of our businesses are included in the documents filed by us with the SEC which we have incorporated by reference into this prospectus supplement. See "Where You Can Find More Information" beginning on page 3 of the accompanying prospectus.

S-6

The Offering

Issuer	UtiliCorp United Inc. 20 West Ninth Street Kansas City, Missouri 64105 Telephone: 816-421-6600
Common stock offered	11,000,000 shares
Approximate number of shares of common stock outstanding after the offering	143.5 million shares
Listing	New York, Pacific and Toronto Stock Exchanges
Symbol	UCU
Indicated annual dividend rate	$1.20 per share, paid quarterly. Purchasers of common stock in this offering are expected to receive any dividend declared in the first quarter of 2002.
Book value per share at September 30, 2001	$22.66
Use of proceeds	Reduction of short-term debt and other short-term obligations, and for general corporate purposes.
Risk factors	See "Risk Factors" and other information included or incorporated by reference in this prospectus supplement and the accompanying prospectus for a discussion of factors you should carefully consider before deciding to invest in shares of our common stock.

        The number of shares outstanding after the offering is based on our shares outstanding as of January 18, 2002. The number of shares outstanding after the offering assumes that the underwriters' over-allotment option is not exercised. If the underwriters exercise their over-allotment option in full, we will issue and sell an additional 1,500,000 shares and will receive additional proceeds before expenses of $                        . See "Underwriting."

S-7

Selected Financial Data

        We are providing the following selected financial information to assist you in analyzing an investment in the shares of our common stock. We derived the financial information presented below as of, and for the nine months ended, September 30, 2001 and 2000 from the unaudited consolidated financial statements included in our Quarterly Report on Form 10-Q for the period ended September 30, 2001. We derived the financial information presented below as of, and for each of the three years in the period ended December 31, 2000 from the audited consolidated financial statements included in our Annual Reports on Form 10-K for those years.

        The financial information below should be read in conjunction with the historical consolidated financial statements and related notes contained in the annual, quarterly and other reports filed by us with the SEC, which we have incorporated by reference into the prospectus.

Selected Consolidated Financial Summary

	As of and for the Nine Months Ended September 30, (unaudited)				As of and for the Year Ended December 31,
	2001(1)		2000		2000(2)		1999		1998(3)
	(in millions, except per share amounts)
Income Statement Data:
Sales	$	31,737	$	18,369	$	28,975	$	18,622	$	12,563
Earnings before interest and taxes		664		399		540		414		351
Net income		286		159		207		161		132
Basic earnings per common share		2.58		1.71		2.22		1.75		1.65
Diluted earnings per common share		2.50		1.69		2.21		1.75		1.63
Cash dividends per common share		.90		.90		1.20		1.20		1.20
Balance Sheet Data:
Current assets		4,774		3,871		6,867		2,272		1,905
Property, plant and equipment, net		3,387		3,159		3,247		3,665		3,314
Total assets		11,878		10,042		14,138		7,539		6,131
Short-term debt (including current maturities)		346		454		553		292		484
Long-term debt		2,140		2,040		2,346		2,202		1,377
Company-obligated preferred securities		350		450		450		350		100
Common shareholder's equity		2,619		1,562		1,800		1,525		1,446

(1)

In 2001, we recorded a $110.8 million pre-tax gain on the sale of 5.75 million shares of Aquila's Class A common stock. EBIT and net income reflect our 80% ownership of Aquila from April 27, 2001 to September 30, 2001.

(2)

In 2000, we recorded $27.2 million of reserves for impairments and other charges relating to underperforming pipeline assets, investments in retail assets in the United Kingdom, certain information technology assets, corporate intangibles and our construction of broadband fiber optic networks. We also recorded a $44.0 million pre-tax gain on the sale of a 34% interest in Uecomm Limited to the public.

(3)

In 1998, we recorded a $27.7 million provision for impairments of retail gas marketing assets and an investment on an independent power project. We also recorded a $45.3 million pre-tax gain on the sale to the public of a 42% interest in United Energy Ltd.

S-8

Selected Unaudited Historical and Pro Forma Consolidated Condensed Financial Data

        We are providing the following selected unaudited historical and pro forma consolidated condensed financial data to show what our results of operations and financial position might have been had the recombination with Aquila been completed at an earlier date. The unaudited and pro forma income statement data for the nine months ended September 30, 2001 give effect to the recombination as if we had completed it as of January 1, 2001. The unaudited pro forma balance sheet data gives effect to the recombination as if we had completed it on September 30, 2001.

        We are providing the following pro forma information for illustrative purposes only. This information does do not purport to be indicative of (1) the results of operations or financial position which would have been achieved if the recombination had been completed at the beginning of the period or as of the date indicated or (2) the results of operations or financial position which may be achieved in the future. This information also does not reflect the effect of any payment that may be required to be made in connection with the exercise of appraisal rights by former Aquila stockholders under Delaware law. The holders of certificates formerly representing 4,704,697 shares of Aquila common stock will have the opportunity to seek appraisal rights.

	Nine Months Ended September 30, 2001
	Historical	Pro Forma
	(in millions, except per share amounts)
Income Statement Data:
Sales	$31,737	$31,737
Earnings before interest and taxes(1)	664	688
Net income and earnings available for common shares(1)	286	310
Basic earnings per common share	2.58	2.48
Diluted earnings per common share	2.50	2.41
Cash dividends per common share	.90	.90

	September 30, 2001
	Historical	Pro Forma
	(in millions)
Balance Sheet Data:
Current assets	$4,774	$4,774
Property, plant and equipment, net	3,387	3,387
Total assets(2)	11,878	12,088
Short-term debt (including current maturities)	346	346
Long-term debt	2,140	2,140
Company-obligated preferred securities	350	350
Common shareholders' equity(3)	2,619	2,978

(1)

Includes the elimination of $23.9 million of minority interest in income of Aquila for the nine months ended September 30, 2001.

(2)

We have allocated the excess of the aggregate purchase price to be paid for Aquila's Class A shares over 20% of the carrying value of Aquila's assets and liabilities to goodwill.

(3)

We exchanged 13,774,760 shares of UtiliCorp common stock, with a value of $26.06 per share, for all 19,975,000 outstanding Class A shares of Aquila, resulting in an aggregate purchase price of $359.0 million.

S-9

RISK FACTORS

        In deciding whether to purchase shares in this offering, you should read carefully this prospectus supplement, the accompanying prospectus and the documents we incorporate by reference into this prospectus supplement and the accompanying prospectus. You should also carefully consider the following factors:

We are exposed to market risk and may incur losses from marketing and trading operations.

        Our Energy Merchant Group routinely enters into financial contracts to position its trading portfolios. These trading portfolios consist of physical and financial gas, electricity, coal, other commodities and interest rate contracts. These contracts take many forms including futures, swaps and options. If the values of these contracts change in a direction or manner that we do not anticipate, we could realize substantial losses as a result of trading activities. We currently enter into financial contracts to hedge or limit our exposure to trading losses. However, these strategies may not prove to be effective and we may still incur substantial losses.

        Although we strictly adhere to established trading guidelines and carefully quantify our market risk using advanced methodologies, you cannot be assured that losses attributable to trading activities will not be material to us. In connection with our Energy Merchant Group's marketing and trading activities, we often extend credit to trading counterparties. While significant credit analysis is performed prior to the extension of credit, the risk exists that parties with whom we enter into contracts might fail to perform their obligations.

We may not be able to make the strategic acquisitions we anticipate or successfully integrate businesses we acquire into our operations.

        A major part of our growth strategy involves making strategic acquisitions. In addition, businesses we do acquire must be integrated into our operations. Our ability to successfully make strategic acquisitions and investments will depend on: (1) the extent to which acquisitions and investment opportunities become available; (2) our success in bidding for the opportunities that do become available; and (3) as described more fully below, our access to capital and the terms upon which we obtain capital. If we are unable to make strategic investments and acquisitions, we may be unable to realize the growth we anticipate. In addition, if we are unable to make strategic investments, our business objectives may be impaired. Our ability to successfully integrate acquired businesses into our operations will depend on: (1) the adequacy and execution of our implementation plans; (2) the ability to achieve desired operating efficiencies; and (3) regulatory approval of the acquisitions on favorable terms. If we are unable to successfully integrate new businesses into our operations, we could experience increased costs and thus lower returns or losses on our investments.

Any reduction in our credit ratings could materially adversely affect our financial condition.

        Our senior unsecured debt has been assigned a rating by Standard & Poor's Rating Services (S&P) of "BBB" (stable outlook), by Moody's Inc. of "Baa3" (positive outlook) and by Fitch, Inc. of "BBB" (negative outlook). While our merchant business has a higher level of risk than our networks business, we will seek to maintain a solid investment grade rating through prudent capital management and financing structures. However, we cannot assure you that any of our current ratings will remain in effect for any given period of time or that a rating will not be lowered or withdrawn entirely by a rating agency if, in its judgment, circumstances in the future so warrant. Any downgrading could have a material adverse effect on our financial condition and our ability to transact our trading business and other operations. While the foregoing indicates the ratings from these agencies, we note that these ratings are not a recommendation to buy, sell or hold our securities and that each rating should be evaluated independently of any other rating.

S-10

Current industry conditions may adversely affect our operations and growth.

        The recent bankruptcy of Enron Corporation has created a heightened concern regarding the creditworthiness of counterparties in energy-related transactions. Counterparties to contracts entered into by our Global Networks Group and Energy Merchant Group could be among those impacted by Enron's bankruptcy or otherwise. If these counterparties are impacted adversely, they may not be able or may refuse to perform under the contracts they have with us, which could adversely impact our operations and financial results.

        The concern over counterparty creditworthiness has also generated a need for additional liquidity among energy companies. We are taking steps to respond to these conditions by issuing shares through this offering and by reducing our planned capital expenditures. However, we cannot assure you that conditions in the energy and capital markets will not continue and may adversely affect our ability to conduct and expand our trading operations and affect our operating results.

We may not be able to implement our strategy if we are unable to access capital at competitive rates.

        If we are not able to access capital at competitive rates, our growth strategy will be adversely affected. A number of factors could affect our ability to access capital including: (1) general economic conditions; (2) capital markets conditions; (3) market prices for electricity and gas; (4) the overall health of the utility and energy merchant industries; (5) our ability to maintain our investment-grade credit ratings; and (6) our capital structure.

S-11

FORWARD LOOKING STATEMENTS

        Many of the statements we make in this prospectus supplement, the accompanying prospectus, and the statements contained in documents we are incorporating by reference are "forward looking statements." These forward looking statements generally can be identified by the use of statements that include words such as "believe," "expect," "anticipate," "should," "intend," "plan," "foresee," "likely," "may," "will" or other similar words or phrases. Similarly, statements that describe our objectives, plans or goals are or may be forward looking statements and are based on assumptions and estimates that we believe are reasonable. All forward looking statements involve risks and uncertainties. In particular, any statements with respect to forecasts, future business strategies and performance are subject to known and unknown risks, uncertainties and contingencies, many of which are beyond our control, which may cause actual forecasted results, performance or achievements to differ materially from anticipated results, performance or achievements. We describe below various risk factors and uncertainties that might affect these forward looking statements:

•

Our business and results of operations may be negatively impacted by adverse changes to general economic conditions and to conditions in the industries in which we operate.



•

Our businesses are weather-sensitive. Weather can affect results significantly to the extent that temperatures differ from normal.



•

We are exposed to market risk, which may cause us to incur losses from our wholesale services operations.



•

We may not be able to implement our strategy if we are unable to access or generate capital at competitive rates.



•

The failure to maintain our investment grade bond rating would increase our borrowing costs.



•

The timing and extent of changes in interest rates could affect our financial results.



•

We may not be able to successfully integrate acquired businesses into our operations.



•

The volatility of natural gas and natural gas liquids prices can significantly affect the earnings contribution from the capacity services segment of our Energy Merchant Group.



•

The pace of well connections to our gas gathering system can affect the earnings contribution from the capacity services segment of our Energy Merchant Group.



•

Our development of merchant power plants may not be successful or profitable.



•

The pace and degree of regulatory changes in the U.S. and abroad can affect new business opportunities and the intensity of competition.



•

The value of the U.S. dollar relative to the British pound, Canadian dollar, Australian dollar and New Zealand dollar can affect financial results from our foreign operations.



•

The results of operations from our Australian businesses may be affected in the near future by the next phase of deregulation, which makes customers contestable and resets rates.



•

The inability to pass through increased fuel and purchased power costs in certain regulatory jurisdictions may affect the results of operations of our networks. The modification of regulations or historical practices in jurisdictions in which we rely upon our ability to recover our costs from our customers could adversely affect our earnings.



•

The result of pending rate proceedings will affect future earnings of our network business.



•

Expansion of electric markets in the United Kingdom and Europe will increase both opportunity and competition in marketing and trading activities.

S-12

•

The construction of broadband fiber optic networks and start-up operations of our communication business will have a negative effect on earnings over the near term.

        Additional factors that might affect our forward looking statements are included in our most recently filed Quarterly Report on Form 10-Q, Current Reports on Form 8-K and Annual Report on Form 10-K, all of which we have incorporated by reference into this prospectus. The factors described above, in the documents we have incorporated by reference and in the "Risk Factors" section of this prospectus supplement are not necessarily all of the important factors that could cause actual results, performance or achievements to differ materially from those expressed in, or implied by, our forward looking statements. Other unknown or unpredictable factors also could have material adverse effects on our future results, performance or achievements. Accordingly, our actual results may differ from those expressed in, or implied by, our forward looking statements. We undertake no obligation to publicly update any forward looking statements, whether as a result of new information, future events or circumstances or otherwise.

S-13

USE OF PROCEEDS

        The proceeds to us from the sale of the shares of our common stock in this offering are expected to be approximately $                      million ($             million if the underwriters' over-allotment option is exercised in full), after deducting the underwriters' discount but before deducting the expenses of this offering. We intend to use the net proceeds to repay a portion of our short-term indebtedness incurred in connection with acquisitions, construction and working capital requirements and for general corporate purposes. Our short-term indebtedness (excluding current maturities of long-term debt) totaled approximately $548.6 million as of December 31, 2001, and had a weighted average interest rate of approximately 3.23%.

PRICE RANGE OF COMMON STOCK AND DIVIDENDS

        Our common stock is traded on the New York, Pacific and Toronto Stock Exchanges under the symbol "UCU." In the following table we present the high and low sales prices per share of our common stock, as reported in the consolidated transaction reporting system, for the quarterly periods presented below. We also present the quarterly dividends paid per share during the applicable periods.

		High		Low		Dividend
2000:
	First Quarter	$	20.06	$	15.19	$	0.30
	Second Quarter		21.88		17.31		0.30
	Third Quarter		28.50		19.88		0.30
	Fourth Quarter		31.31		23.94		0.30
2001:
	First Quarter	$	32.40	$	24.81	$	0.30
	Second Quarter		37.85		29.35		0.30
	Third Quarter		33.00		26.60		0.30
	Fourth Quarter		31.80		21.85		0.30
2002:
	First Quarter (through January 18)	$	26.70	$	25.34	$	—

        As of January 18, 2002, there were approximately 132.5 million shares of our common stock outstanding and approximately 40,000 holders of record of our common stock.

        The holders of our common stock receive dividends if and when declared by our board of directors out of legally available funds. As noted above, we currently pay dividends at an annual rate of $1.20 per share. We expect to continue paying quarterly dividends on a basis consistent with our recent practice. However, our board's declaration and payment of dividends will depend upon business conditions, operating results and our board of directors' consideration of other relevant factors. No assurance can be given that we will continue to pay dividends on our common stock at the current annual rate in the future. Purchasers of common stock in this offering are expected to receive any dividend declared in the first quarter of 2002.

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CAPITALIZATION

        The following table sets forth our unaudited short-term debt and capitalization as of September 30, 2001 on an actual basis and on an unaudited adjusted basis reflecting (a) the sale of 11,000,000 shares of our common stock offered pursuant to this offering and the application of the net proceeds as described under "Use of Proceeds" and (b) the issuance of 13,774,760 shares of our common stock in recombination with Aquila as described in the Summary to this Prospectus Supplement.

					As of September 30, 2001
					Actual			As Adjusted	% Capitalization
					(in millions)
Short-term debt, including current maturities					$	346.1
Long-term debt						2,139.6
Company-obligated preferred securities						350.0
Common shareholders' equity:
	Common stock, authorized 400,000,000, par value
		$1 per share, 115,584,624 issued; Class A
		common stock, authorized 20,000,000, par value
		$1 per share, none issued				115.6
	Premium on capital stock					2,041.1
	Retained earnings					520.5
	Treasury stock, at cost					(0.2	)
	Accumulated other comprehensive losses					(58.2	)
			Total common shareholders' equity			2,618.8
				Total capitalization	$	5,454.5		$	100.0	%

S-15

UNDERWRITING

        Salomon Smith Barney Inc., UBS Warburg LLC, Deutsche Banc Alex. Brown and Credit Lyonnais Securities (USA) Inc. are acting as representatives of each of the underwriters named below. Subject to the terms and conditions set forth in a purchase agreement among us and the underwriters, we have agreed to sell to the underwriters, and each of the underwriters severally and not jointly has agreed to purchase from us, the number of shares of common stock set forth opposite its name below.

Underwriter		Number of Shares
Salomon Smith Barney Inc.
UBS Warburg LLC.
Deutsche Banc Alex. Brown
Credit Lyonnais Securities (USA) Inc.
	Total	11,000,000

        The underwriters have agreed, subject to the terms and conditions contained in the purchase agreement, to purchase all of the shares of common stock sold under the purchase agreement if any of these shares are purchased. If an underwriter defaults, the purchase agreement provides that the purchase commitments of the non-defaulting underwriters may be increased or the purchase agreement may be terminated. The closings of the sale of shares of common stock to the underwriters are conditioned upon one another.

        The underwriters are offering the shares subject to prior sale, when, as and if issued to and accepted by them, subject to approval of legal matters by their counsel, including the validity of the shares, and other conditions contained in the purchase agreement, such as the receipt by the underwriters of officer's certificates and legal opinions. The underwriters reserve the right to withdraw, cancel or modify offers to the public and to reject orders in whole or in part.

Commissions and Discounts

        The representatives have advised us that the underwriters propose initially to offer the shares of common stock to the public at the public offering price on the cover page of this prospectus supplement and to certain dealers at that price less a concession not in excess of $                              per share. The underwriters may allow, and the dealers may reallow, a discount not in excess of $                              per share on sales to other dealers. After the initial public offering, the public offering price, concession and discount may be changed.

        The following table shows the public offering price, underwriting discount and proceeds before expenses to us. This information assumes either no exercise or full exercise by the underwriters of their over-allotment option.

	Per Share	Without Option	With Option
Public offering price	$	$	$
Underwriting discount	$	$	$
Proceeds, before expenses, to UtiliCorp United Inc.	$	$	$

        The expenses of this offering, not including the underwriting discount, are estimated at $                  and are payable by us.

S-16

Over-Allotment Option

        We have granted an option to the underwriters to purchase up to 1,500,000 additional shares of common stock at the public offering price on the cover page of this prospectus supplement, less the underwriting discount. The underwriters may exercise this option for 30 days from the date of this prospectus supplement solely to cover over-allotments. If the underwriters exercise this option, each underwriter will be obligated, subject to conditions contained in the purchase agreement, to purchase a number of additional shares proportionate to that underwriter's initial amount reflected in the table.

No Sales of Similar Securities

        We have agreed, with exceptions, not to sell or transfer any of our common stock for 90 days after the date of this prospectus supplement without first obtaining the written consent of the representatives. Specifically, we have agreed not to directly or indirectly:

•

Offer, pledge, sell or contract to sell any common stock;



•

Sell any option or contract to purchase any common stock;



•

Purchase any option or contract to sell any common stock;



•

Grant any option, right or warrant for the sale of any common stock;



•

Lend or otherwise dispose of or transfer any common stock;



•

File a registration statement related to our common stock pursuant to a request or demand; or



•

Enter into swap or other agreement that transfers, in whole or in part, the economic consequence of ownership of any common stock whether any such swap or transaction is to be settled by delivery of shares or other securities, in cash or otherwise.

        This lockup provision applies to common stock and to securities convertible into or exchangeable or exercisable for or repayable with common stock.

Indemnification

        We have agreed to indemnify the underwriters against certain liabilities, including certain liabilities under the Securities Act of 1933, or to contribute to payments the underwriters may be required to make in respect of those liabilities.

Price Stabilization and Short Position

        Until the distribution of the common stock offered hereby is completed, Securities and Exchange Commission rules may limit the underwriters and selling group members from bidding for or purchasing our common stock. However, the representatives may engage in transactions that stabilize the price of the common stock, such as bids or purchases to peg, fix or maintain that price.

        If the underwriters create a short position in the common stock in connection with the offering, i.e., if they sell more shares than are listed on the cover page of this prospectus supplement, the representatives may reduce that short position by purchasing common stock in the open market. The representatives may also elect to reduce any short position by exercising all or part of the over-allotment option described above. Purchases of our common stock to stabilize or reduce a short position could cause the price of our common stock to be higher than it might be in the absence of such purchases.

        Neither we nor any of the underwriters makes any representation or prediction as to the direction or magnitude of any effect that the transactions described above may have on the price of the common stock. In addition, neither we nor any of the underwriters makes any representation that the

S-17

representative will engage in these transactions or that these transactions, once commenced, will not be discontinued without notice.

Other Relationships

        Some of the underwriters or their affiliates have provided investment or commercial banking services to us in the past and are likely to do so in the future. They receive customary fees and commissions for these services.

LEGAL MATTERS

        The legality of the common stock will be passed upon by Blackwell Sanders Peper Martin LLP, Two Pershing Square, 2300 Main Street, Kansas City, Missouri 64108, and certain matters will be passed upon for the underwriters by Milbank, Tweed, Hadley & McCloy LLP, 1 Chase Manhattan Plaza, New York, New York 10005. Milbank, Tweed, Hadley & McCloy LLP from time to time provides legal services to us.

S-18

P R O S P E C T U S

$500,000,000
15,000,000 Shares

SENIOR NOTES
COMMON STOCK

        We will provide specific terms of these securities in supplements to this prospectus. You should read this prospectus and any supplement carefully before you invest.

        Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

This Prospectus is dated September 21, 2001

TABLE OF CONTENTS

About This Prospectus	2
Where You Can Find More Information	3
The Company	3
Use of Proceeds	3
Ratio of Earnings to Fixed Charges	4
Description of Common Stock	4
Description of Senior Notes	8
Plan of Distribution	12
Experts	13

ABOUT THIS PROSPECTUS

        This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission utilizing a "shelf" registration process. Under this shelf process, we may, from time to time, sell in one or more offerings senior notes up to a total dollar amount of $500,000,000 and up to 15,000,000 shares of common stock. This prospectus provides you with a general description of the securities we may offer. Each time we sell securities, we will provide a prospectus supplement that will contain specific information about the terms of that offering. The prospectus supplement may also add, update or change information contained in this prospectus. You should read both this prospectus and any prospectus supplement together with additional information described under the heading "Where You Can Find More Information." Unless otherwise indicated or unless the context requires otherwise, all references in this prospectus to "UtiliCorp," "we," "our," "us," or similar references mean UtiliCorp United Inc. and all of our subsidiaries.

2

WHERE YOU CAN FIND MORE INFORMATION

        We file annual, quarterly and special reports, proxy statements and other information with the Securities and Exchange Commission. You may read and copy any materials that we file at the Commission's Public Reference Room at 450 Fifth Street, N.W., Washington, D.C. 20549. You may obtain information regarding the operation of the Public Reference Room by calling the Commission at 1-800-SEC-0330. We file information electronically with the Commission. The Commission maintains an Internet site that contains the reports, proxy and information statements and other information regarding issuers that file electronically. The address of the Commission's Internet site is http://www.sec.gov.

        The Commission allows us to "incorporate by reference" the information we file with them, which means that we can disclose important information to you by referring you to other documents. This information incorporated by reference is considered part of this prospectus, and information that we file later with the Commission will automatically update and supersede this information. We incorporate by reference the documents listed below and any future filings we make with the Commission under Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934:

a.

Annual Report on Form 10-K for the fiscal year ended December 31, 2000.



b.

Quarterly Reports on Form 10-Q for the fiscal quarters ended March 31 and June 30, 2001.



c.

Current Reports on Form 8-K dated February 2 and February 23, 2001.



d.

The description of common stock contained in our Registration Statement on Form 8-B dated May 5, 1987 and the description of the preference stock purchase rights set forth in our Registration Statement on Form 8-A dated March 4, 1997.

You may request a copy of these filings, at no cost, by telephoning or writing to us at the following address:

Investor Relations
UtiliCorp United Inc.
20 West Ninth Street
Kansas City, Missouri 64105
816-421-6600

        Additionally, you can get further information about us on our website, http://www.utilicorp.com. We do not, however, intend for the information on our website to constitute part of this prospectus.

        This prospectus is part of a registration statement we filed with the Commission. You should rely only on the information contained in this prospectus and in any prospectus supplement. We have not authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it.

THE COMPANY

        We are a multinational energy and energy services company headquartered in Kansas City, Missouri. Our executive offices are located at 20 West Ninth Street, Kansas City, Missouri 64105 and our telephone number is 816-421-6600.

USE OF PROCEEDS

        Unless otherwise set forth in a prospectus supplement, the net proceeds from the sale of the offered securities will be used for general corporate purposes including repayment of debt, construction and acquisitions.

3

RATIO OF EARNINGS TO FIXED CHARGES

        Our ratio of earnings to fixed charges for each of the periods indicated is as follows:

	Twelve Months Ended June 30,	Years Ended December 31,
	2001	2000	1999	1998	1997	1996
Ratio of Earnings to Fixed Charges	3.20	2.05	2.03	2.01	2.29	1.79

        The ratio of earnings to fixed charges represents the number of times fixed charges are covered by earnings. For the purpose of these ratios, earnings consist of income before provisions for income taxes and fixed charges less undistributed earnings in equity investments. For this purpose, fixed charges comprise (1) interest on all indebtedness and amortization of debt discount and expense, (2) interest capitalized and (3) an interest factor attributable to rentals.

DESCRIPTION OF COMMON STOCK

General

        The following description of our common stock is a summary and is not complete. You should refer to our governing corporate documents and our Michigan Gas Utilities Indenture, dated as of July 1, 1951, which secures the first mortgage bonds issued by Michigan Gas Utilities Company and assumed by us in connection with our acquisition of Michigan Gas Utilities Company in 1989.

        We are authorized to issue up to 430,000,000 shares of capital stock consisting of:

•

400,000,000 shares of common stock, par value $1 per share;



•

10,000,000 shares of preference stock, without par value; and



•

20,000,000 shares of Class A common stock, par value $1 per share.

Dividend Rights and Limitations

        Subject to the limitation referred to below, our board of directors may declare dividends on our capital stock out of funds legally available for that purpose.

        Cash dividends on our capital stock are restricted by provisions of the Michigan Gas Utilities Indenture. Under the most restrictive of these provisions, we may not declare or pay any dividend, other than a dividend payable in shares of our capital stock, if, after giving effect to the dividend, the sum of:

•

the aggregate amount of all dividends declared and all other distributions made, other than dividends declared or distributions made in shares of our capital stock, subsequent to December 31, 1984; plus



•

the excess, if any, of the amount applied to or set apart for the acquisition of any shares of our capital stock subsequent to December 31, 1984, over amounts received by us as the net cash proceeds of sales of shares of our capital stock subsequent to that date, would exceed the sum of our net income since January 1, 1985, plus $50 million.

        In addition, we may not declare dividends unless we maintain a tangible net worth of at least $250 million and the total principal amount of our outstanding indebtedness does not exceed 70% of our capitalization. None of our retained earnings was restricted as to payment of cash dividends on our capital stock as of June 30, 2001.

4

Voting Rights

        Holders of our common stock are entitled to one vote for each share held of record. Our board of directors is divided into three classes, and each year one class is elected to serve a three-year term. Holders of common stock do not have cumulative voting in the election of directors. Accordingly, the holders of more than 50% of the outstanding shares of our common stock voting for the election of directors can elect all the directors, and the remaining holders will not be able to elect any directors.

Liquidation Rights

        Our outstanding common stock is, and the common stock that may be offered from time to time, when issued and paid for will be, fully paid and non-assessable. Holders of common stock do not have any preemptive rights. On liquidation, the holders of the common stock will be entitled to all amounts remaining for distribution after payment of the liquidation preferences of the outstanding shares, if any, of the Class A common stock and the preference stock.

Class A Common Stock and Preference Stock

        Without action by our stockholders, our board of directors may issue one or more series of Class A common stock or preference stock that may have terms more favorable than the common stock, including preferential dividend, liquidation, redemption and voting rights.

        We may use the Class A common stock or the preference stock as an anti-takeover device because these securities may be issued with "super voting" rights and placed in the control of parties aligned with current management. However, the NYSE has in effect a rule that restricts our ability to issue Class A common stock and preference stock with super voting rights. There are presently no shares of Class A common stock or preference stock issued or outstanding.

Stockholder Rights Plan

        We have adopted a stockholder rights plan under which our stockholders have been granted one preference stock purchase right for each share of common stock held. The following description of the purchase rights is not complete. You should refer to the Rights Agreement we entered into with First Chicago Trust Company of New York on December 31, 1996, a copy of which we filed with the Commission as an exhibit to our Form 8-A Registration Statement filed on March 4, 1997.

        Each purchase right, when it becomes exercisable as described below, entitles the holder to purchase one-thousandth of a share of our Series A Participating Cumulative Preference Stock, no par value, at a purchase price of $76.67, subject to certain adjustments and other specified conditions.

        The purchase rights become exercisable upon the occurrence of a "distribution date," which is defined in the rights agreement as the earlier of:

•

the tenth business day, or such later date as our board of directors may fix, after the date on which any company commences a tender or exchange offer which, if consummated, would result in the company acquiring ownership of more than 15% of our outstanding common stock; or



•

the "flip-in date," which means the tenth business day after we first publicly announce that a company has acquired ownership of more than 15% of our outstanding common stock, or such other date as our board of directors may adopt prior to the flip-in date that would otherwise have occurred.

        The rights agreement does not apply to certain acquisitions, including acquisitions by a company that inadvertently acquires ownership of more than 15% of our outstanding common stock, provided the company promptly divests sufficient shares of common stock to reduce its percentage ownership below 15%.

5

        If a flip-in date occurs, each purchase right, other than purchase rights the acquiring company or any of its affiliates beneficially own, will constitute the right to purchase from us that number of shares of our common stock having a market value equal to twice the exercise price of the purchase right. On the occurrence of a flip-in date, the purchase rights beneficially owned by the acquiring company or any of its affiliates will be void.

        In addition, our board of directors may, at its option, at any time after a flip-in date and prior to the time the acquiring company becomes the owner of more than 50% of the outstanding shares of our common stock, elect to exchange all of the outstanding purchase rights, other than those purchase rights beneficially owned by the acquiring company or its affiliates, for shares of our common stock at an exchange ratio of one share of our common stock per purchase right. Immediately upon the taking of that action by our board of directors, the right to exercise the purchase rights will terminate and each purchase right will then represent only the right to receive the appropriate number of shares of common stock.

        Whenever we become obligated to issue shares of common stock upon the exercise of or in exchange for purchase rights, we may substitute shares of preference stock, at a ratio of one one-thousandth of a share of preference stock for each share of common stock.

        If we are acquired in a merger or other similar business combination entered into while:

•

the acquiring company or any of its affiliates is in control of our board of directors or 50% or more of our assets; or



•

assets representing 50% or more of our operating income or cash flow are transferred to an acquiring company or any of its affiliates,

then we are required to take all necessary action to ensure that the purchase rights will "flip-over" and entitle each holder of a purchase right to purchase capital stock of the acquiring company having a market value equal to twice the purchase price of the preference stock otherwise purchasable pursuant to the purchase right.

        At any time prior to the earlier of a flip-in date and the tenth anniversary of the rights agreement, our board of directors may redeem the purchase rights in whole, but not in part, at a price of $0.01 per purchase right. Under certain circumstances the rights agreement may be amended by our board of directors without approval from our stockholders.

        The purchase rights have an anti-takeover effect. Specifically, the purchase rights may cause substantial dilution to a person or group that attempts to acquire a substantial number of shares of our common stock without the approval of our board of directors. The purchase rights will not interfere with any merger or other business combination with a third party approved by our board of directors, because the board of directors may, at any time prior to a flip-in date, redeem the purchase rights as described above or amend the rights agreement to render it inapplicable to a specific transaction.

Additional Anti-Takeover Defenses

        A number of provisions in our governing corporate documents may have the effect of discouraging other companies from acquiring large blocks of our common stock or delaying or preventing a change of control of UtiliCorp. For instance, because our certificate of incorporation authorizes our board of directors to issue additional capital stock without stockholder approval, the board of directors could issue additional shares of stock to discourage a change of control of UtiliCorp. Furthermore, the absence of cumulative voting rights could discourage accumulations of large blocks of our common stock by purchasers seeking representation on our board of directors.

6

        Other provisions in our certificate of incorporation are designed to discourage attempts to obtain control of UtiliCorp in a transaction not approved by our board of directors. Such provisions include:

•

an 80% stockholder vote requirement to remove the entire board of directors;



•

a prohibition against the removal of individual directors without cause;



•

a requirement that the board of directors be divided into three classes, with one class elected each year for a three-year term;



•

an 80% stockholder vote requirement to amend provisions of the certificate of incorporation relating to our board of directors;



•

an 80% stockholder vote requirement to approve certain business transactions, unless certain minimum price conditions are met;



•

an 80% stockholder vote requirement to amend the above-listed provisions;



•

a requirement that stockholder action may be taken only at an annual or special meeting; and



•

a requirement that special meetings may be called by not less than a majority of the stockholders.

        Our bylaws also contain provisions that may have an anti-takeover effect, including:

•

advance notice requirements for stockholder nominations to our board of directors; and



•

a requirement that nominating stockholders provide information comparable to that which we would be required to provide under federal securities laws.

These bylaw provisions could enable us to delay undesirable stockholder actions in order to give us more time and information to adequately respond.

        As previously described, our stockholder rights plan also has an anti-takeover effect. Severance agreements we have entered into with certain of our management employees may have anti-takeover effects as well. Such severance agreements provide that we must pay certain benefits if the employees are terminated without good cause or resign for good reason, as defined in the agreements, within three years after a change of control of UtiliCorp.

Transfer Agent and Registrar

        The co-transfer agents for our common stock are:

•

Equiserve Trust Company, N.A., Jersey City, New Jersey;



•

UMB Bank, N.A., Kansas City, Missouri; and



•

The R-M Trust Company, Toronto, Ontario, Canada.

        The registrar for the common stock is Equiserve Trust Company, N.A. of Jersey City, New Jersey. Our common stock is listed on the New York, Pacific and Toronto Stock Exchanges, and unless the prospectus supplement accompanying this prospectus states otherwise, the common stock offered under this prospectus will be listed on those exchanges.

7

DESCRIPTION OF SENIOR NOTES

        We may issue senior notes from time to time in one or more series, under an Indenture dated as of August 24, 2001, as supplemented, between us and BankOne Trust Company, N.A., as the trustee. The indenture has been filed as an exhibit to the registration statement of which this prospectus is a part. The following description of certain provisions of the indenture is a summary and is not complete. You should refer to all of the provisions of the indenture, including the definitions of certain terms contained in the indenture. A copy of the indenture may be obtained from us upon request.

General

        The indenture does not limit the aggregate principal amount of the senior notes or the aggregate principal amount of any particular series of senior notes that we may issue under the indenture. The indenture states that we may issue senior notes from time to time in one or more series. The senior notes will be unsecured obligations and will rank equally with all of our other unsecured and unsubordinated indebtedness.

        The specific terms of each series of senior notes will be set forth in the prospectus supplement relating to that series, including the following terms, if possible:

•

the title of the senior notes;



•

the aggregate principal amount of the series of senior notes and any limit on the aggregate principal amount of that series;



•

the price (expressed as a percentage of the aggregate principal amount) at which we will issue the series of senior notes;



•

the maturity date or dates for the series of senior notes;



•

the interest rate or rates (which may be fixed or variable) per annum for the series of senior notes, if any, or any method by which the interest rate or rates, will be determined;



•

the date or dates:



•

from which the interest, if any, will accrue;



•

on which the interest, if any, will be payable;



•

on which payment of the interest, if any, will commence; and



•

of record for any interest payments;

•

the person, if different than the registered holder as of the record date, to whom any interest will be payable;



•

the dates, if any, on which and the price at which the series of senior notes may be redeemed or purchased under any mandatory sinking fund provisions, and the other detailed terms and provisions of the sinking funds;



•

the date, if any, after which and the price at which we or any holder of the senior notes may redeem the senior notes and other detailed terms and provisions of the optional redemptions;



•

any additional restrictive covenants included in the supplemental indentures solely for the benefit of the series of senior notes;



•

any additional events of default (as defined below) solely with respect to the series of senior notes;

8

•

the currency or currencies in which we will pay the principal of (and premium, if any) or interest, if any, on the series of senior notes;



•

the index, if any, used to determine the amount of principal of (and premium, if any) and interest, if any on the series of senior notes;



•

whether we will use a global security with respect to the series of senior notes, the name of the depository for the global security and the terms, if any, upon which interests in the global security may be exchanged for definitive senior notes; and



•

any additional terms of the series of the senior notes.

        Unless the applicable prospectus supplement states otherwise, we will pay the principal, and the premium and interest, if any, on the series of senior notes at the office or agency we maintain in New York, New York for that purpose. In addition, the transfer or exchange of the senior notes will be registerable at that same office. We may, however, pay interest by check mailed to the address as it appears on the security register of any person entitled to payment of interest. (Sections 301, 305 and 1002).

        Unless the applicable prospectus supplement states otherwise, we will only issue the senior notes in registered form without coupons and in denominations of $1,000 and integral multiples of $1,000. (Section 302). No service charge will be made for any registration of transfer or exchange of the senior notes, but we may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection with the transfer or exchange. (Section 305).

        We may issue senior notes as original issue discount securities (as defined below) meaning that they will be sold at a discount below their principal amount. We will describe special federal income tax, accounting and other considerations applicable to original issue discount securities in the prospectus supplement. "Original issue discount security" is any security that provides for the acceleration of the maturity of an amount less than the principal amount of the security upon the occurrence and continuance of an event of default. (Section 101).

Events of Default

        With respect to any series of senior notes, the indenture defines an event of default as:

•

a default in the payment of principal, (or premium, if any), on any debt security at its maturity;



•

a default in the payment of any interest on any debt security for 30 days;



•

a default in the payment of any sinking fund installment;



•

our failure to perform any other of the covenants or warranties in the indenture for 60 days after we receive notice of our failure (other than a covenant or warranty included in the indenture solely for the benefit of a series of senior notes other than that particular series);



•

a default by us under any indebtedness for money we have borrowed resulting in indebtedness in an aggregate principal amount exceeding $10,000,000 becoming due prior to maturity, if the acceleration of that indebtedness is not rescinded within 10 days after notice of such default;



•

certain events of bankruptcy, insolvency or reorganization of UtiliCorp; and



•

any other event of default provided with respect to senior notes of that series. (Section 501).

        If any event of default with respect to any series of senior notes at the time outstanding occurs and is continuing, either the trustee or the holders of at least 25% in principal amount of the outstanding senior notes of that series may, by notice, declare the principal amount (or, if the senior notes are original issue discount securities, such portion of the principal amount as may be specified in the terms of that series) of all senior notes of that series to be due and payable immediately. Upon certain

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conditions the holders of a majority in principal amount of the outstanding senior notes of that series on behalf of the holders of all senior notes of that series may annul that declaration and waive past defaults. A declaration may not, however, be annulled if the default is a default in payment of principal of, or premium or interest, if any, on the senior notes and other specified defaults unless that default has been cured. (Section 502 and 513).

        The prospectus supplement relating to each series of outstanding senior notes which are original issue discount securities will contain the particular provisions relating to acceleration of the maturity of a portion of the principal amount of those original issue discount securities if an event of default occurs and continues.

        The indenture states that the trustee will give notice to the holders of any series of senior notes of a known default if that default is uncured or not waived. The trustee may decide to withhold a notice of default if it determines in good faith that withholding of the notice is in the interest of the holders of the senior notes unless the default is in the payment of principal (or premium, if any) or interest, if any, on any debt security of that series, or in the payment of any sinking fund installment. The trustee may not give notice of default until 30 days after the occurrence of a default in the performance of a covenant in the indenture other than for the payment of the principal of (or premium, if any) or interest, if any, or the deposit of any sinking fund installment. The term default with respect to any series of outstanding senior notes for the purpose only of this provision means the happening of any of the events of default specified in the indenture and relating to such series of outstanding senior notes, excluding any grace periods and irrespective of any notice requirements. (Section 602).

        The indenture contains a provision entitling the trustee, subject to the duty of the trustee during default to act with the required standard of care, to be indemnified by the holders of any series of outstanding senior notes before proceeding to exercise any right or power under the indenture at the request of the holders of that series of senior notes. (Section 603). The indenture states that the holders of a majority in principal amount of outstanding senior notes of any series may direct the time, method and place of conducting any proceeding for any remedy available to the trustee, or exercising any trust or other power conferred on the trustee. The trustee, however, may decline to act if that direction is contrary to law or the indenture. (Section 512).

        The indenture requires us to annually file with the trustee a certificate stating that no default exists or identifying any existing default.

Defeasance

        At our option, we:

•

will be discharged from all obligations with respect to the senior notes (except for certain obligations including registering the transfer or exchange of the senior notes, replacing stolen, lost or mutilated senior notes, maintaining paying agencies and holding monies for payment in trust); or



•

need not comply with certain restrictive covenants of the indenture,

if we deposit with the trustee (and in the case of a discharge, 91 days after such deposit) money, or U.S. government obligations, or a combination of both, sufficient to pay all the principal of and interest on the senior notes on the date those payments are due in accordance with the terms of the senior notes to and including a redemption date which we irrevocably designate for redemption of the senior notes. To exercise this option, we must meet certain conditions, including delivering to the trustee an opinion of counsel stating that the deposit and related defeasance will not cause the holders of the senior notes to recognize income, gain or loss for federal income tax purposes. (Sections 403 and 1008).

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Modification of the Indenture

        With respect to any series of senior notes we and the trustee may add provisions to or change or eliminate any of the provisions of the indenture relating to that series if holders of at least a majority in principal amount of that series of senior notes, voting as a class, consent. We and the trustee cannot, however, modify the indenture to:

•

change the stated maturity of any senior note;



•

reduce the principal amount of, or the rate of interest or any premium on, any senior note;



•

change the place or currency of payment on any senior note;



•

impair the right to institute suit for the enforcement of any payment on or after the stated maturity of any security;



•

reduce the percentage of outstanding senior notes necessary to modify or amend the indenture; or



•

reduce the percentage of aggregate principal amount of outstanding senior notes necessary to waive compliance with certain provisions of the indenture or to waive certain covenants and defaults. (Section 902).

Consolidations, Merger and Sale of Assets

        Without the consent of the holders of any of the outstanding senior notes under the indenture, we may:

•

consolidate with or merge into any other corporation;



•

transfer or lease substantially all of our assets to any person;



•

acquire or lease substantially all of the assets of any person; or



•

permit any corporation to merge into us, if:



•

the successor is a corporation organized under the laws of any domestic jurisdiction;



•

the successor corporation, if other than us, assumes our obligations on the senior notes and under the indenture; and



•

after giving the effect to the transaction, no event of default, and no event which, after notice or lapse of time, would become an event of default, will occur. (Section 801).

        Certain of the covenants described above will not necessarily afford the holders protection in the event we are involved in a highly leveraged transaction, such as a leveraged buyout. However, we must obtain regulatory approval to issue long-term debt.

Outstanding Senior Notes

        In determining whether the holders of the requisite principal amount of outstanding senior notes have given any request, demand, authorization, direction, notice, consent or waiver under the indenture, the following are taken into account:

•

the portion of the principal amount of an original issue discount security deemed to be outstanding is that portion of the principal amount that could be declared to be due and payable upon the occurrence and continuation of an event of default under the terms of the original issue discount security as of the date of the determination, and



•

senior notes we or any of our affiliates own are not considered to be outstanding. (Section 101).

Regarding the Trustee

        We have a bank line of credit and maintain depository and other banking relationships with Bank One, N.A., an affiliate of the trustee.

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PLAN OF DISTRIBUTION

        We may sell the securities in any of four ways:

•

through underwriters or dealers;



•

directly to a limited number of institutional purchasers or to a single purchaser;



•

through agents; or



•

through direct sales or auctions performed by utilizing the Internet or a bidding or ordering system.

        Any underwriter, dealer or agent, may be deemed to be an underwriter within the meaning of the Securities Act of 1933. The terms of the offering of the securities with respect to which this prospectus is being delivered will be set forth in the applicable prospectus supplement and will include:

•

the name or names of any underwriters, dealers or agents;



•

the purchase price of the securities and the proceeds to us from such sale;



•

any underwriting discounts and other items constituting underwriters' compensation;



•

the public offering price; and



•

any discounts or concessions which may be allowed or reallowed or paid to dealers and any securities exchanges on which the securities may be listed.

        If underwriters are used in the sale of securities, the securities will be acquired by the underwriters for their own account and may be resold from time to time in one or more transactions, including negotiated transactions, at a fixed public offering price or at varying prices determined at the time of sale. The securities may be offered to the public either through underwriting syndicates represented by managing underwriters or directly by one or more underwriters acting alone. Unless otherwise set forth in the applicable prospectus supplement, the obligations of the underwriters to purchase the securities described in the applicable prospectus supplement will be subject to certain conditions precedent, and the underwriters will be obligated to purchase all of the securities if any are so purchased by them. Any public offering price and any discounts or concessions allowed or reallowed or paid to dealers may be changed from time to time.

        The securities may be sold from time to time directly by us through agents designated by us. Any agents involved in the offer or sale of the securities in respect of which this prospectus is being delivered, and any commissions payable by us to such agents, will be set forth in the applicable prospectus supplement. Unless otherwise indicated in the applicable prospectus supplement, any agent will be acting on a best efforts basis for the period of its appointment.

        If dealers are utilized in the sale of any securities, we will sell the securities to the dealers as principals. Any dealer may resell the securities to the public at varying prices to be determined by the dealer at the time of resale. The name of any dealer and the terms of the transaction will be set forth in the prospectus supplement with respect to the securities being offered.

        Securities may also be offered and sold, if so indicated in the applicable prospectus supplement, in connection with a remarketing upon their purchase, in accordance with a redemption or repayment pursuant to their terms, or otherwise, by one or more firms, which we refer to herein as the "remarketing firms," acting as principals for their own accounts or as our agents. Any remarketing firm will be identified and the terms of its agreement, if any, with us and its compensation will be described in the applicable prospectus supplement. Remarketing firms may be deemed to be underwriters, as that term is defined in the Securities Act in connection with the securities remarketed thereby.

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        If so indicated in the applicable prospectus supplement, we will authorize agents, underwriters or dealers to solicit offers by certain specified institutions to purchase the securities to which this prospectus and the applicable prospectus supplement relates from us at the public offering price set forth in the applicable prospectus supplement, plus, if applicable, accrued interest, pursuant to delayed delivery contracts providing for payment and delivery on a specified date in the future. These contracts will be subject only to those conditions set forth in the applicable prospectus supplement, and the applicable prospectus supplement will set forth the commission payable for solicitation of the contracts.

        Underwriters will not be obligated to make a market in any securities. No assurance can be given regarding the activity of trading in, or liquidity of, any securities.

        Agents, dealers, underwriters and remarketing firms may be entitled, under agreements entered into with us, to indemnification by us against certain civil liabilities, including liabilities under the Securities Act, or to contribution to payments they may be required to make in respect thereof. Agents, dealers, underwriters and remarketing firms may be customers of, engage in transactions with, or perform services for, us in the ordinary course of business.

        Each series of securities will be a new issue and, other than the common stock, which is currently listed on the New York, Pacific and Toronto Stock Exchanges, will have no established trading market. We may elect to list any series of securities on an exchange, and in the case of the common stock, on any additional exchange, but, unless otherwise specified in the applicable prospectus supplement, we shall not be obligated to do so. No assurance can be given as to the liquidity of the trading market for any of the securities.

        We may also offer senior notes directly to the public, with or without the involvement of agents, underwriters or dealers and may utilize the Internet or another electronic bidding or ordering system for the pricing and allocation of such senior notes. Such a system may allow bidders to directly participate, through electronic access to an auction site, by submitting conditional offers to buy that are subject to acceptance by us, and which may directly affect the price or other terms at which such securities are sold.

        The final offering price at which senior notes would be sold and the allocation of senior notes among bidders, would be based in whole or in part on the results of the Internet bidding process or auction. Many variations of the Internet auction or pricing and allocating systems are likely to be developed in the future, and we may utilize such systems in connection with the sale of Senior Notes. We will describe in the related supplement to this prospectus how any auction or bidding process will be conducted to determine the price or any other terms of the Senior Notes, how potential investors may participate in the process and, when applicable, the nature of the underwriters' obligations with respect to the auction or ordering system.

EXPERTS

        Our annual consolidated financial statements and schedules incorporated in this prospectus by reference from our 2000 Annual Report on Form 10-K have been audited by Arthur Andersen LLP, independent public accounts, as indicated in their report with respect thereto, and are incorporated herein in reliance upon the authority of said firm as experts in giving said reports.

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11,000,000 Shares

Common Stock

PROSPECTUS SUPPLEMENT

Joint Book-Running Managers

Salomon Smith Barney UBS Warburg

Co-Managers

Deutsche Banc Alex. Brown

Credit Lyonnais Securities (USA) Inc.

January      , 2002.

QuickLinks

TABLE OF CONTENTS Prospectus Supplement
SUMMARY
Our Company
Global Networks Group
Energy Merchant Group
Our Strategy
Recent Developments
The Offering
Selected Financial Data
Selected Consolidated Financial Summary
Selected Unaudited Historical and Pro Forma Consolidated Condensed Financial Data
RISK FACTORS
FORWARD LOOKING STATEMENTS
USE OF PROCEEDS
PRICE RANGE OF COMMON STOCK AND DIVIDENDS
CAPITALIZATION
UNDERWRITING
LEGAL MATTERS
ABOUT THIS PROSPECTUS
WHERE YOU CAN FIND MORE INFORMATION
THE COMPANY
USE OF PROCEEDS
RATIO OF EARNINGS TO FIXED CHARGES
DESCRIPTION OF COMMON STOCK
DESCRIPTION OF SENIOR NOTES
PLAN OF DISTRIBUTION
EXPERTS