OPPENHEIMER DEVELOPING MARKETS FUND

497 1 developingmarketssupp.htm PROSPECTUS AND SAI SUPPLEMENT OPPENHEIMER DEVELOPING MARKETS FUND

Supplement dated February 18, 2005
to the Prospectus dated October 27, 2004

This supplement amends the Prospectus dated October 27, 2004.

This Prospectus is revised as follows:

1. In the section entitled "How Can You Buy Class A Shares?", the following is added after
the chart depicting Class A share sales charges on page 19.

Due to rounding, the actual sales charge for a particular transaction may be higher
or lower than the rates listed above.

2. Effective March 18, 2005, the first two sentences of the first paragraph of the
section entitled "Right of Accumulation" in the section entitled "Can You Reduce Class A
Sales Charges?" on page 20 are replaced with the following:

To qualify for the reduced Class A sales charge that would apply to a larger
purchase than you are currently making (as shown in the table above), you can
add the value of any Class A, Class B or Class C shares of the Fund or other
Oppenheimer funds that you or your spouse currently own, or are currently
purchasing, to the value of your Class A share purchase. Your Class A shares of
Oppenheimer Money Market Fund, Inc. or Oppenheimer Cash Reserves on which you
did not pay a sales charge will not be counted for this purpose.

3. Effective March 18, 2005, the first paragraph of the section entitled "Letters of
Intent" in the section entitled "Can You Reduce Class A Sales Charges?" on page 20 is
replaced with the following:

You may also qualify for reduced Class A sales charges by submitting a Letter
of Intent to the Distributor. A Letter of Intent is a written statement of your
intention to purchase a specified value of Class A, Class B or Class C shares
of the Fund or other Oppenheimer funds over a 13-month period. The total amount
of your intended purchases of Class A, Class B and Class C shares will
determine the reduced sales charge rate that will apply to your Class A share
purchases of the Fund during that period. You can choose to include purchases
made up to 90 days before the date that you submit a Letter. Your Class A
shares of Oppenheimer Money Market Fund, Inc. or Oppenheimer Cash Reserves on
which you did not pay a sales charge will not be counted for this purpose.
Submitting a Letter of Intent does not obligate you to purchase the specified
amount of shares. You can also apply the Right of Accumulation to these
purchases.

4. The section titled "Pending Litigation" at the end of section of the Prospectus
captioned "ABOUT THE FUND - HOW THE FUND IS MANAGED," on page 13, should be deleted in its
entirety and replaced with the following:

PENDING LITIGATION. A consolidated amended complaint has been filed as putative
derivative and class actions against the Manager, Distributor and Transfer
Agent, as well as 51 of the Oppenheimer funds (collectively the "funds")
including the Fund, 31 present and former Directors or Trustees and 9 present
and former officers of certain of the Funds. This complaint, filed in the U.S.
District Court for the Southern District of New York on January 10, 2005,
consolidates into a single action and amends six individual previously-filed
putative derivative and class action complaints. Like those prior complaints,
the complaint alleges that the Manager charged excessive fees for distribution
and other costs, improperly used assets of the funds in the form of directed
brokerage commissions and 12b-1 fees to pay brokers to promote sales of the
funds, and failed to properly disclose the use of fund assets to make those
payments in violation of the Investment Company Act and the Investment Advisers
Act of 1940. Also, like those prior complaints, the complaint further alleges
that by permitting and/or participating in those actions, the Directors/Trustees
and the Officers breached their fiduciary duties to Fund shareholders under the
Investment Company Act and at common law. The complaint seeks unspecified
compensatory and punitive damages, rescission of the funds' investment advisory
agreements, an accounting of all fees paid, and an award of attorneys' fees and
litigation expenses.

The Manager and the Distributor believe the claims asserted in these law
suits to be without merit, and intend to defend the suits vigorously. The
Manager and the Distributor do not believe that the pending actions are likely
to have a material adverse effect on the Fund or on their ability to perform
their respective investment advisory or distribution agreements with the Fund.

5. The section titled "How to Exchange Shares" in the section of the Prospectus captioned
"ABOUT YOUR ACCOUNT," on page 30, should be deleted in its entirety and replaced with the
following:

How to Exchange Shares

If you want to change all or part of your investment from one Oppenheimer fund to another,
you can exchange your shares for shares of the same class of another Oppenheimer fund that
offers the exchange privilege. For example, you can exchange Class A shares of the Fund
only for Class A shares of another fund. To exchange shares, you must meet several
conditions:

o Shares of the fund selected for exchange must be available for sale in your state of
residence.
o The prospectuses of the selected fund must offer the exchange privilege.
o You must hold the shares you buy when you establish an account for at least seven
days before you can exchange them. After your account is open for seven days, you can
exchange shares on any regular business day, subject to the limitations described
below.
o You must meet the minimum purchase requirements for the selected fund.
o Generally, exchanges may be made only between identically registered accounts, unless
all account owners send written exchange instructions with a signature guarantee.
o Before exchanging into a fund, you must obtain its prospectus and should read it.

For tax purposes, an exchange of shares of the Fund is considered a sale of those
shares and a purchase of the shares of the fund to which you are exchanging. An exchange
may result in a capital gain or loss.

You can find a list of the Oppenheimer funds that are currently available for
exchanges in the Statement of Additional Information or you can obtain a list by calling a
service representative at 1.800.225.5677. The funds available for exchange can change from
time to time. There are a number of other special conditions and limitations that apply to
certain types of exchanges. In some cases, sales charges may be imposed on exchange
transactions. In general, a contingent deferred sales charge (CDSC) is not imposed on
exchanges of shares that are subject to a CDSC. However, if you exchange shares that are
subject to a CDSC, the CDSC holding period will be carried over to the acquired shares, and
the CDSC may be imposed if those shares are redeemed before the end of that holding period.
These conditions and circumstances are described in detail in the "How to Exchange Shares"
section in the Statement of Additional Information.

HOW DO you SUBMIT EXCHANGE REQUESTS? Exchanges may be requested in writing, by telephone or
the internet, or by establishing an Automatic Exchange Plan.

Written Exchange Requests. Send an OppenheimerFunds Exchange Request form, signed by all
owners of the account, to the Transfer Agent at the address on the back cover.
Exchanges of shares for which share certificates have been issued cannot be processed
unless the Transfer Agent receives the certificates with the request.

Telephone and Internet Exchange Requests. Telephone exchange requests may be made either by
calling a service representative or by using PhoneLink by calling 1.800.225.5677. You
may submit internet exchange requests on the OppenheimerFunds internet website, at
www.oppenheimerfunds.com. You must have obtained a user I.D. and password to make
------------------------
transactions on that website. Telephone and/or internet exchanges may be made only
between accounts that are registered with the same name(s) and address. Shares for
which share certificates have been issued may not be exchanged by telephone or the
internet.

Automatic Exchange Plan. Shareholders can authorize the Transfer Agent to exchange a
pre-determined amount of shares automatically on a monthly, quarterly, semi-annual or
annual basis.

Please refer to "How to Exchange Shares" in the Statement of Additional Information for
more details.

ARE THERE LIMITATIONS ON FREQUENT PURCHASES, REDEMPTIONS AND EXCHANGES?

Risks from Excessive Purchase, Redemption and Short-Term Exchange Activity. The
OppenheimerFunds exchange privilege affords investors the ability to switch their
investments among Oppenheimer funds if their investment needs change. However, there are
limits on that privilege. Frequent purchases, redemptions and exchanges of fund shares may
interfere with the Manager's ability to manage the fund's investments efficiently, increase
the fund's transaction and administrative costs and/or affect the fund's performance,
depending on various factors, such as the size of the fund, the nature of its investments,
the amount of fund assets the portfolio manager maintains in cash or cash equivalents, the
aggregate dollar amount and the number and frequency of trades. If large dollar amounts are
involved in exchange and/or redemption transactions, the Fund might be required to sell
portfolio securities at unfavorable times to meet redemption or exchange requests, and the
Fund's brokerage or administrative expenses might be increased.

Therefore, the Manager and the Fund's Board of Trustees have adopted the following policies
and procedures to detect and prevent frequent and/or excessive exchanges, and/or purchase
and redemption activity, while balancing the needs of investors who seek liquidity from
their investment and the ability to exchange shares as investment needs change. There is no
guarantee that the policies and procedures described below will be sufficient to identify
and deter excessive short-term trading.

o Timing of Exchanges. Exchanged shares are normally redeemed from one fund and the
proceeds are reinvested in the fund selected for exchange on the same regular
business day on which the Transfer Agent or its agent (such as a financial
intermediary holding the investor's shares in an "omnibus" or "street name" account)
receives an exchange request that conforms to these policies. The request must be
received by the close of The New York Stock Exchange that day, which is normally 4:00
p.m. Eastern time, but may be earlier on some days. However, the Transfer Agent may
delay the reinvestment of proceeds from an exchange for up to five business days if
it determines, in its discretion, that an earlier transmittal of the redemption
proceeds to the receiving fund would be detrimental to either the fund from which the
exchange is made or the fund to which the exchange is made.

o Limits on Disruptive Activity. The Transfer Agent may, in its discretion, limit or
terminate trading activity by any person, group or account that it believes would be
disruptive, even if the activity has not exceeded the policy outlined in this
Prospectus. The Transfer Agent may review and consider the history of frequent
trading activity in all accounts in the Oppenheimer funds known to be under common
ownership or control as part of the Transfer Agent's procedures to detect and deter
excessive trading activity.

o Exchanges of Client Accounts by Financial Advisers. The Fund and the Transfer Agent
permit dealers and financial intermediaries to submit exchange requests on behalf of
their customers (unless the customer has revoked that authority). The Distributor
and/or the Transfer Agent have agreements with a number of financial intermediaries
that permit them to submit exchange orders in bulk on behalf of their clients. Those
intermediaries are required to follow the exchange policy stated in this Prospectus
and to comply with additional, more stringent restrictions. Those additional
restrictions include limitations on the funds available for exchanges, the
requirement to give advance notice of exchanges to the Transfer Agent, and limits on
the amount of client assets that may be invested in a particular fund. A fund or the
Transfer Agent may limit or refuse bulk exchange requests submitted by such financial
intermediaries if, in the Transfer Agent's judgment, exercised in its discretion, the
exchanges would be disruptive to any of the funds involved in the transaction.

o Redemptions of Shares. These exchange policy limits do not apply to redemptions of
shares. Shareholders are permitted to redeem their shares on any regular business
day, subject to the terms of this Prospectus. The Fund assesses a 2% fee on the
proceeds of Fund shares that are redeemed or exchanged within 30 days after their
purchase in certain circumstances. Further details are provided under "How to Sell
Shares."

o Right to Refuse Exchange and Purchase Orders. The Distributor and/or the Transfer
Agent may refuse any purchase or exchange order in their discretion and are not
obligated to provide notice before rejecting an order. The Fund may amend, suspend or
terminate the exchange privilege at any time. You will receive 60 days' notice of any
material change in the exchange privilege unless applicable law allows otherwise.

o Right to Terminate or Suspend Account Privileges. The Transfer Agent may send a
written warning to direct shareholders who the Transfer Agent believes may be
engaging in excessive purchases, redemptions and/or exchange activity and reserves
the right to suspend or terminate the ability to purchase shares and/or exchange
privileges for any account that the Transfer Agent determines, in carrying out these
policies and in the exercise of its discretion, has engaged in disruptive or
excessive trading activity.

o Omnibus Accounts. If you hold your shares of the Fund through a financial
intermediary such as a broker-dealer, a bank, an insurance company separate account,
an investment adviser, an administrator or trustee of a retirement plan or 529 plan
that holds your shares in an account under its name (these are sometimes referred to
as "omnibus" or "street name" accounts), that financial intermediary may impose its
own restrictions or limitations to discourage short-term or excessive trading. You
should consult your financial intermediary to find out what trading restrictions,
including limitations on exchanges, they may apply to you.

While the Fund, the Distributor, the Manager and the Transfer Agent encourage financial
intermediaries to apply the Fund's policies to their customers who invest indirectly in the
Fund, the Transfer Agent may not be able to apply this policy to accounts such as (a)
accounts held in omnibus form in the name of a broker-dealer or other financial
institution, or (b) omnibus accounts held in the name of a retirement plan or 529 plan
trustee or administrator, or (c) accounts held in the name of an insurance company for its
separate account(s), or (d) other accounts having multiple underlying owners but registered
in a manner such that the underlying beneficial owners are not identified to the Transfer
Agent.

Therefore the Transfer Agent might not be able to detect excessive short term trading
activity facilitated by, or in accounts maintained in, the "omnibus" or "street name"
accounts of a financial intermediary. However, the Transfer Agent will attempt to monitor
overall purchase and redemption activity in those accounts to seek to identify patterns
that may suggest excessive trading by the underlying owners. If evidence of possible
excessive trading activity is observed by the Transfer Agent, the financial intermediary
that is the registered owner will be asked to review account activity, and to confirm to
the Transfer Agent and the fund that appropriate action has been taken to curtail any
excessive trading activity. However, the Transfer Agent's ability to monitor and deter
excessive short-term trading in omnibus or street name accounts ultimately depends on the
capability and cooperation of the financial intermediaries controlling those accounts.

The Fund's Board has adopted additional policies and procedures to detect and prevent
frequent and/or excessive exchanges and purchase and redemption activity. Those additional
policies and procedures will take effect on June 20, 2005:

o 30-Day Limit. A direct shareholder may exchange all or some of the shares of the
Fund held in his or her account to another eligible Oppenheimer fund once in a 30
calendar-day period. When shares are exchanged into another fund account, that
account will be "blocked" from further exchanges into another fund for a period of 30
calendar days from the date of the exchange. The block will apply to the full account
balance and not just to the amount exchanged into the account. For example, if a
shareholder exchanged $1,000 from one fund into another fund in which the shareholder
already owned shares worth $10,000, then, following the exchange, the full account
balance ($11,000 in this example) would be blocked from further exchanges into
another fund for a period of 30 calendar days. A "direct shareholder" is one whose
account is registered on the Fund's books showing the name, address and tax ID number
of the beneficial owner.

o Exchanges Into Money Market Funds. A direct shareholder will be permitted to
exchange shares of a stock or bond fund for shares of a money market fund at any
time, even if the shareholder has exchanged shares into the stock or bond fund during
the prior 30 days. However, all of the shares held in that money market fund would
then be blocked from further exchanges into another fund for 30 calendar days.

o Dividend Reinvestments/B Share Conversions. Reinvestment of dividends or
distributions from one fund to purchase shares of another fund and the conversion of
Class B shares into Class A shares will not be considered exchanges for purposes of
imposing the 30-day limit.
o Asset Allocation. Third-party asset allocation and rebalancing programs will be
subject to the 30-day limit described above. Asset allocation firms that want to
exchange shares held in accounts on behalf of their customers must identify
themselves to the Transfer Agent and execute an acknowledgement and agreement to
abide by these policies with respect to their customers' accounts. "On-demand"
exchanges outside the parameters of portfolio rebalancing programs will be subject to
the 30-day limit. However, investment programs by other Oppenheimer "funds-of-funds"
that entail rebalancing of investments in underlying Oppenheimer funds will not be
subject to these limits.

o Automatic Exchange Plans. Accounts that receive exchange proceeds through automatic
or systematic exchange plans that are established through the Transfer Agent will not
be subject to the 30-day block as a result of those automatic or systematic exchanges
(but may be blocked from exchanges, under the 30-day limit, if they receive proceeds
from other exchanges).

February 18, 2005 PS0785.021

OPPENHEIMER DEVELOPING MARKETS FUND

Supplement dated February 18, 2005 to the
Statement of Additional Information dated October 27, 2004 and
revised February 3, 2005

This supplement amends the Statement of Additional Information dated October 27, 2004 and
revised February 3, 2005.

The Statement of Additional Information is revised as follows:

1. Effective March 18, 2005, the first three paragraphs of the section entitled "Letters of
Intent" on page 55 are replaced with the following:

Letters of Intent. Under a Letter of Intent ("Letter"), you can reduce the sales charge
rate that applies to your purchases of Class A shares if you purchase Class A, Class B
or Class C shares of the Fund or other Oppenheimer funds during a 13-month period. The
total amount of your purchases of Class A, Class B and Class C shares will determine the
sales charge rate that applies to your Class A share purchases during that period. You
can choose to include purchases made up to 90 days before the date of the Letter. Class
A shares of Oppenheimer Money Market Fund, Inc. and Oppenheimer Cash Reserves fund on
which you did not pay a sales charge and any Class N shares you purchase, or may have
purchased, will not be counted towards satisfying the purchases specified in a Letter.

A Letter is an investor's statement in writing to the Distributor of his or her
intention to purchase a specified value of Class A, Class B and Class C shares of the
Fund and other Oppenheimer funds during a 13-month period (the "Letter period"). At the
investor's request, this may include purchases made up to 90 days prior to the date of
the Letter. The Letter states the investor's intention to make the aggregate amount of
purchases of shares which, when added to the investor's holdings of shares of those
funds, will equal or exceed the amount specified in the Letter. Purchases made by
reinvestment of dividends or capital gains distributions and purchases made at net asset
value (i.e. without a sales charge) do not count toward satisfying the amount of the
Letter.

Each purchase of Class A shares under the Letter will be made at the offering
price (including the sales charge) that would apply to a single lump-sum purchase of
shares in the amount intended to be purchased under the Letter.

2. The following is added to the end of the section entitled "Waivers of Initial and
Contingent Deferred Sales Charges in Certain Transactions" on page B-4 of Appendix B:

|_| Shares purchased in amounts of less than $5.

February 18, 2005 PX0785.011