Filing under Rule 425 under the U.S. Securities Act of 1933
Filing by: Nippon Oil Corporation
Subject Companies: Nippon Oil Corporation and
Nippon Mining Holdings, Inc.
Commission File Number: 333-164036
Dated January 12, 2010

Postcard

Postage paid

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Nippon Oil Corporation

Contact Information for the Shareholder Register Administrator:

The Chuo Mitsui Trust and Banking Company, Limited
8-4, Izumi 2-chome, Suginami-ku, Tokyo, Japan, 168-0063
(Stock Transfer Business Center)
Tel: 0120-78-2031 (toll-free)

To request forms please call the number below or consult the website below:
Tel: 0120-87-2031 (toll-free)
Website: http://www.chuomitsui.co.jp/person/p_06.html

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January 12, 2010

To Shareholders with Voting Rights

Shinji Nishio
Representative Director, President
Nippon Oil Corporation
3-12, Nishi-Shimbashi 1-chome,
Minato-ku, Tokyo, Japan

EXERCISING YOUR VOTING RIGHTS AT THE EXTRAORDINARY
GENERAL MEETING OF SHAREHOLDERS

Dear Shareholder:

Thank you for your continued support of Nippon Oil Corporation (the “Company”).

As previously notified in the “Notice of the Extraordinary General Meeting of Shareholders” (the “Notice”), the Extraordinary General Meeting of Shareholders of the Company will be held on January 27, 2010 (Wednesday).

In the event that you are unable to attend, please indicate your approval or disapproval of the proposals on the agenda on the voting card enclosed with the Notice, and return the card to the Company, or read the “How to Exercise Voting Rights by an Electronic Method (e.g., via the Internet)” section on pages 38 and 39 of the Notice and enter your approval or disapproval of the proposals on the agenda.

Please disregard this postcard if you have already voted using one of the above methods prior to receiving this postcard.

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Filings with the U.S. Securities and Exchange Commission

Nippon Oil Corporation and Nippon Mining Holdings, Inc. have filed a registration statement on Form F-4 with the U.S. Securities and Exchange Commission (the “SEC”) in connection with the proposed joint share transfer. The Form F-4 contains a prospectus and other documents. The registration statement on Form F-4 has been declared effective, and Nippon Oil Corporation and Nippon Mining Holdings, Inc. have arranged to mail the prospectus contained in the Form F-4 to their respective U.S. shareholders prior to the shareholders’ meeting at which the proposed joint share transfer will be voted upon. The Form F-4 and prospectus, as they may be amended from time to time, contain important information about Nippon Oil Corporation and Nippon Mining Holdings, Inc., the joint share transfer and related matters including the terms and conditions of the transaction. U.S. shareholders of Nippon Oil Corporation and Nippon Mining Holdings, Inc. are urged to read the Form F-4, the prospectus and the other documents, as they may be amended from time to time, filed with the SEC in connection with the joint share transfer carefully before they make any decision at the shareholders meeting with respect to the joint share transfer. The Form F-4, the prospectus and all other documents filed with the SEC in connection with the joint share transfer are available, free of charge, on the SEC’s web site at www.sec.gov. In addition, the prospectus and all other documents filed with the SEC in connection with the joint share transfer will be made available to shareholders of Nippon Oil Corporation and Nippon Mining Holdings, Inc., free of charge, by faxing a request to Nippon Oil Corporation at +81-3-3502-9860 or Nippon Mining Holdings, Inc. at +81-3-5573-5139, respectively.

Cautionary Statement Regarding Forward-Looking Statements

This announcement contains certain forward-looking statements. These forward-looking statements may be identified by words such as ‘believes’, ‘expects’, ‘anticipates’, ‘projects’, ‘intends’, ‘should’, ‘seeks’, ‘estimates’, future’ or similar expressions or by discussion of, among other things, strategy, goals, plans or intentions. Actual results may differ materially in the future from those reflected in forward-looking statements contained in this document, due to various factors including but not limited to: (1) macroeconomic condition and general industry conditions such as the competitive environment for companies in energy, resources and materials industries; (2) regulatory and litigation matters and risks; (3) legislative developments; (4) changes in tax and other laws and the effect of changes in general economic conditions; (5) the risk that a condition to closing of the transaction may not be satisfied; (6) the risk that a regulatory approval that may be required for the transaction is not obtained or is obtained subject to conditions that are not anticipated; and (7) other risks to consummation of the transaction.

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