Citigroup (C)

The board of directors has unanimously approved and declared advisable each of the Common Stock Amendments and unanimously recommends that you give your Proxy Instructions pursuant to the Letter of Transmittal to approve each of the Common Stock Amendments.

The proxy statement enclosed with this letter provides you with important information about the matters for which we are seeking your Proxy Instructions pursuant to the Letter of Transmittal. We encourage you to read

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the entire proxy statement carefully. You may also obtain additional information about us from documents we have filed with the SEC and on our website at www.citigroup.com.

This letter is being sent to you as a holder of Public Preferred Depositary Shares or Trust Preferred Securities. As a holder of Public Preferred Depositary Shares or Trust Preferred Securities, you may only give your Proxy Instructions (and you will be required to give your Proxy Instructions) pursuant to the Letter of Transmittal to approve each of the Common Stock Amendments to the extent that you tender your Public Preferred Depositary Shares or Trust Preferred Securities for shares of common stock in the Exchange Offers. Accordingly, in order to give your Proxy Instructions in respect of these matters (and in order to be permitted to participate in the Exchange Offers), you need only comply with the requirements for participating in the Exchange Offers set forth in the Prospectus and the Letter of Transmittal.

If you hold your Public Preferred Depositary Shares or Trust Preferred Securities through a bank, broker, custodian or other nominee and wish to participate in the Exchange Offers, please contact your bank, broker, custodian or other nominee to instruct it to tender your Public Preferred Depositary Shares or Trust Preferred Securities in accordance with the instructions in the Prospectus and the Letter of Transmittal and grant your Proxy Instructions pursuant to the Letter of Transmittal. Due to the time required for your bank, broker, custodian or other nominee to complete the required actions on your part, we urge you to contact your bank, broker, custodian or other nominee at least five business days prior to the expiration date of the Exchange Offers.

Thank you for your support of Citigroup.

Sincerely,

Richard D. Parsons

Chairman of the Board

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Citigroup Inc.

399 Park Avenue

New York, NY 10043

June 18, 2009

Dear Common Stockholder:

We are writing to you to request that you grant your proxy authorizing the individuals pre-printed on the enclosed proxy card to execute a written consent in respect of the shares of common stock that you hold as of the Record Date (as defined below) to approve the following proposed amendments to our restated certificate of incorporation. These proposals have been unanimously approved and declared advisable by the board of directors:

The effectiveness of any Common Stock Amendment is not conditioned on the approval of any other Common Stock Amendment.

In order to save the expense associated with holding a special meeting, the board of directors has elected to obtain stockholder approval of the amendments described above by written consent pursuant to Section 228 of the Delaware General Corporation Law, rather than by calling a meeting of stockholders. We are soliciting proxies from all of the holders as of the Record Date of our common stock that was not issued in the Exchange Offers (as defined below) to authorize the individuals designated by Citigroup on the enclosed proxy card to execute a written consent in favor of the Common Stock Amendments. We are also soliciting Proxy Instructions (as defined in the enclosed proxy statement) from holders of our Public Preferred Depositary Shares (as defined below) and Trust Preferred Securities (as defined below), in respect of the shares of common stock that may be issued to them in the Exchange Offers in exchange for such Public Preferred Depositary Shares and Trust Preferred Securities.

Granting your proxy authorizing the individuals designated by Citigroup on the enclosed proxy card to execute a written consent to approve the Common Stock Amendments is important for the success of the transactions that we announced on February 27, 2009 to strengthen our tangible common equity (TCE) and Tier 1

The board of directors has unanimously approved and declared advisable each of the Common Stock Amendments and unanimously recommends that you grant a proxy to the individuals named on the enclosed proxy card to execute a written consent to approve each of the Common Stock Amendments.

If you are a record holder of common stock that was not issued in the Exchange Offers and is outstanding and entitled to vote on the Record Date, you are urged to complete, date and sign the enclosed proxy card and promptly return it in the enclosed postage-prepaid envelope or vote by telephone or Internet by following the instructions on the enclosed proxy card. To be counted, your dated and signed proxy card must be received prior to the close of business on September 2, 2009 (the Proxy Deadline). Citigroup may, subject to applicable law, extend the Proxy Deadline in its sole discretion and will announce any such extension by issuing a press release. If you hold your common stock through a bank, broker, custodian or other nominee, please contact your bank, broker, custodian or other nominee to instruct it to grant a proxy on your behalf with respect to each of the Common Stock Amendments.

If you held Public Preferred Depositary Shares or Trust Preferred Securities, we previously sent you a copy of this proxy statement in connection with the Exchange Offers. ANY PREVIOUSLY GRANTED PROXY INSTRUCTIONS GIVEN WITH RESPECT TO YOUR PUBLIC PREFERRED DEPOSITARY SHARES OR TRUST PREFERRED SECURITIES WILL NOT HAVE ANY EFFECT WITH RESPECT TO SHARES OF COMMON STOCK THAT WERE NOT ISSUED IN THE EXCHANGE OFFERS. IN ORDER TO TAKE ACTION ON THE COMMON STOCK AMENDMENTS WITH RESPECT TO SHARES OF COMMON STOCK THAT WERE NOT ISSUED IN THE EXCHANGE OFFERS, YOU MUST DATE AND SIGN THE ENCLOSED PROXY CARD AND RETURN IT PROMPTLY IN THE ENCLOSED POSTAGE-PREPAID ENVELOPE OR VOTE BY TELEPHONE OR INTERNET BY FOLLOWING THE INSTRUCTIONS ON THE ENCLOSED PROXY CARD.

The proxy statement enclosed with this letter provides you with important information about the matters for which we are seeking your proxy to grant a written consent. We encourage you to read the entire proxy statement carefully. You may also obtain additional information about us from documents we have filed with the Securities and Exchange Commission and on our website at www.citigroup.com.

Regardless of the number of shares you own, your proxy is important. Please complete, date and sign the enclosed proxy card and return it promptly in the enclosed envelope so that we receive your response on or before the Proxy Deadline, subject to extension by the board of directors. We will announce any extension of the Proxy Deadline by issuing a press release. You may also grant your proxy over the Internet or by telephone on or before the Proxy Deadline. Please review the instructions on the enclosed proxy card regarding each of these options.

Thank you for your support of Citigroup.

Sincerely,

Richard D. Parsons

Chairman of the Board

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Citigroup Inc.

399 Park Avenue

New York, NY 10043

The board of directors has unanimously approved and declared advisable each of the Common Stock Amendments and unanimously recommends that you follow the procedures contained in the Letter of Transmittal to give your Proxy Instructions to approve each of the Common Stock Amendments.

By order of the Board of Directors

Michael S. Helfer

Corporate Secretary

June 18, 2009

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Citigroup Inc.

399 Park Avenue

New York, NY 10043