As filed with the Securities and Exchange Commission on July 18, 2008

Registration No. 333-88280

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

POST-EFFECTIVE AMENDMENT NO. 3

FORM S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

Aquila, Inc.

(Exact Name of Registrant as Specified in Its Charter)

Delaware		44-0541877
(State or Other Jurisdiction of Incorporation or Organization)		(I.R.S. Employer Identification No.)

20 West Ninth Street

Kansas City, Missouri 64105

(816) 421-6600

(Address, Including Zip Code, and Telephone Number, Including Area Code, of Registrant’s Principal Executive Offices)

Mark G. English

General Counsel and Assistant Corporate Secretary

Great Plains Energy Incorporated

1201 Walnut Street

Kansas City, Missouri 64106-2124

(816) 556-2200

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Approximate date of commencement of proposed sale to the public:

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box. ¨

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box. ¨

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ¨

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ¨

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box.

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer x	Accelerated filer ¨

Non-accelerated filer ¨ (Do not check if a smaller reporting company)	Smaller Reporting Company ¨

DEREGISTRATION OF SECURITIES

On July 14, 2008, Aquila Inc., a Delaware corporation (“Aquila”), consummated a merger transaction (the “Merger”) in which Great Plains Energy Incorporated, acquired all the outstanding shares of Aquila. As a result of the Merger, the common stock, par value $1.00 per share, of Aquila ceased to trade on The New York Stock Exchange and became eligible for delisting from The New York Stock Exchange and termination of registration pursuant to Section 12(g)(4) and Rule 12h-3 of the Securities Exchange Act of 1934, as amended.

The purpose of this Post-Effective Amendment No. 3 to the Registration Statement on Form S-3 (Registration File No. 333-88280) (the “Registration Statement”) is to terminate the effectiveness of such Registration Statement and to deregister all of the securities originally registered thereby which remain unsold as of such termination. The Registration Statement is a “shelf” registration statement under which Aquila could from time to time sell in one or more offerings any combination of its common stock, senior notes, stock purchase contracts and stock purchase units up to a total dollar amount of $1 billion. Aquila has sold $743,550,000 of securities pursuant to the Registration Statement, and hereby deregisters the remaining $256,450,000 of securities which remain unsold as of the termination of this Registration Statement.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrant has duly caused this Post-Effective Amendment to Form S-3 to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Kansas City, State of Missouri, on the 18th day of July, 2008.

	AQUILA, INC.

	By:	/s/ William H. Downey
		Name: William H. Downey
		Title: President and Chief Executive Officer

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed by the following persons in the capacities and on the dates indicated.

	Signature	Title	Date

	/s/ William H. Downey	President and Chief Executive	July 18, 2008
	William H. Downey	Officer and Director (Principal
		Executive Officer)

	/s/ Terry Bassham	Chief Financial Officer	July 18, 2008
	Terry Bassham	(Principal Financial Officer)

	/s/ Lori A. Wright	Controller	July 18, 2008
	Lori A. Wright	(Principal Accounting Officer)

	*	Director	July 18, 2008
	David L. Bodde

	/s/ Michael J. Chesser	Chairman of the Board	July 18, 2008
	Michael J. Chesser

	*	Director	July 18, 2008
	Mark A. Ernst

	*	Director	July 18, 2008
	Randall C. Ferguson, Jr.

	*	Director	July 18, 2008
	Luis A. Jimenez

	*	Director	July 18, 2008
	James A. Mitchell

	*	Director	July 18, 2008
	William C. Nelson

	*	Director	July 18, 2008
	Linda H. Talbott

*By:	/s/ Michael J. Chesser
	Michael J. Chesser
	Attorney-in-Fact

EXHIBIT INDEX

Exhibit Number		Description

24.1		Powers of Attorney (Exhibit 24.1 to Aquila, Inc.’s Post-Effective Amendment to Form S-3 Registration Statement (File 333-88280) filed with the Commission on July 15, 2008).