SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No.__)* Mentor Graphics Corporation (Name of Issuer) Common Stock, without par value (Title of Class of Securities) 587200106 (CUSIP Number) Marc Weitzen Icahn Capital LP 767 Fifth Avenue, 47th Floor New York, New York 10153 (212) 702-4300 (Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications) May 17, 2010 (Date of Event which Requires Filing of this Statement) If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of Section 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box / /. NOTE: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7 for other parties to whom copies are to be sent. *The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page. The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes). SCHEDULE 13D CUSIP No. 587200106 1. NAME OF REPORTING PERSON High River Limited Partnership 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 1,463,764 8 SHARED VOTING POWER 0 9 SOLE DISPOSITIVE POWER 1,463,764 10 SHARED DISPOSITIVE POWER 0 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,463,764 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 1.37% 14 TYPE OF REPORTING PERSON PN SCHEDULE 13D CUSIP No. 587200106 1. NAME OF REPORTING PERSON Hopper Investments LLC 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 1,463,764 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 1,463,764 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,463,764 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 1.37% 14 TYPE OF REPORTING PERSON OO SCHEDULE 13D CUSIP No. 587200106 1. NAME OF REPORTING PERSON Barberry Corp. 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 1,463,764 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 1,463,764 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,463,764 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 1.37% 14 TYPE OF REPORTING PERSON CO SCHEDULE 13D CUSIP No. 587200106 1. NAME OF REPORTING PERSON Icahn Partners Master Fund LP 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 2,512,189 8 SHARED VOTING POWER 0 9 SOLE DISPOSITIVE POWER 2,512,189 10 SHARED DISPOSITIVE POWER 0 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,512,189 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 2.35% 14 TYPE OF REPORTING PERSON PN SCHEDULE 13D CUSIP No. 587200106 1. NAME OF REPORTING PERSON Icahn Partners Master Fund II LP 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 879,444 8 SHARED VOTING POWER 0 9 SOLE DISPOSITIVE POWER 879,444 10 SHARED DISPOSITIVE POWER 0 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 879,444 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.82% 14 TYPE OF REPORTING PERSON PN SCHEDULE 13D CUSIP No. 587200106 1. NAME OF REPORTING PERSON Icahn Partners Master Fund III LP 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 331,801 8 SHARED VOTING POWER 0 9 SOLE DISPOSITIVE POWER 331,801 10 SHARED DISPOSITIVE POWER 0 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 331,801 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.31% 14 TYPE OF REPORTING PERSON PN SCHEDULE 13D CUSIP No. 587200106 1. NAME OF REPORTING PERSON Icahn Offshore LP 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 3,723,434 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 3,723,434 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 3,723,434 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 3.49% 14 TYPE OF REPORTING PERSON PN SCHEDULE 13D CUSIP No. 587200106 1. NAME OF REPORTING PERSON Icahn Partners LP 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 2,131,625 8 SHARED VOTING POWER 0 9 SOLE DISPOSITIVE POWER 2,131,625 10 SHARED DISPOSITIVE POWER 0 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,131,625 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 2.00% 14 TYPE OF REPORTING PERSON PN SCHEDULE 13D CUSIP No. 587200106 1. NAME OF REPORTING PERSON Icahn Onshore LP 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 2,131,625 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 2,131,625 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,131,625 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 2.00% 14 TYPE OF REPORTING PERSON PN SCHEDULE 13D CUSIP No. 587200106 1. NAME OF REPORTING PERSON Icahn Capital LP 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 5,855,059 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 5,855,059 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 5,855,059 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.49% 14 TYPE OF REPORTING PERSON PN SCHEDULE 13D CUSIP No. 587200106 1. NAME OF REPORTING PERSON IPH GP LLC 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 5,855,059 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 5,855,059 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 5,855,059 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.49% 14 TYPE OF REPORTING PERSON OO SCHEDULE 13D CUSIP No. 587200106 1. NAME OF REPORTING PERSON Icahn Enterprises Holdings L.P. 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 5,855,059 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 5,855,059 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 5,855,059 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.49% 14 TYPE OF REPORTING PERSON PN SCHEDULE 13D CUSIP No. 587200106 1. NAME OF REPORTING PERSON Icahn Enterprises G.P. Inc. 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 5,855,059 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 5,855,059 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 5,855,059 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.49% 14 TYPE OF REPORTING PERSON CO SCHEDULE 13D CUSIP No. 587200106 1. NAME OF REPORTING PERSON Beckton Corp. 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS WC 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 5,855,059 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 5,855,059 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 5,855,059 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.49% 14 TYPE OF REPORTING PERSON CO SCHEDULE 13D CUSIP No. 587200106 1 NAME OF REPORTING PERSON Carl C. Icahn 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 SOURCE OF FUNDS 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) / / 6 CITIZENSHIP OR PLACE OF ORGANIZATION United States of America NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 7 SOLE VOTING POWER 0 8 SHARED VOTING POWER 7,318,823 9 SOLE DISPOSITIVE POWER 0 10 SHARED DISPOSITIVE POWER 7,318,823 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 7,318,823 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES / / 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 6.86% 14 TYPE OF REPORTING PERSON IN SCHEDULE 13D Item 1. Security and Issuer This statement relates to the Common Stock, without par value (the "Shares"), issued by Mentor Graphics Corporation (the "Issuer"). The address of the principal executive offices of the Issuer is 8005 S.W. Boeckman Road, Wilsonville, Oregon 97070-7777. Item 2. Identity and Background The persons filing this statement are High River Limited Partnership ("High River"), Hopper Investments LLC ("Hopper"), Barberry Corp. ("Barberry"), Icahn Partners Master Fund LP ("Icahn Master"), Icahn Partners Master Fund II LP ("Icahn Master II"), Icahn Partners Master Fund III LP ("Icahn Master III"), Icahn Offshore LP ("Icahn Offshore"), Icahn Partners LP ("Icahn Partners"), Icahn Onshore LP ("Icahn Onshore"), Icahn Capital LP ("Icahn Capital"), IPH GP LLC ("IPH"), Icahn Enterprises Holdings L.P. ("Icahn Enterprises Holdings"), Icahn Enterprises G.P. Inc. ("Icahn Enterprises GP"), Beckton Corp. ("Beckton"), and Carl C. Icahn, a citizen of the United States of America (collectively, the "Reporting Persons"). The principal business address of each of (i) High River, Hopper, Barberry, Icahn Offshore, Icahn Partners, Icahn Onshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP and Beckton is White Plains Plaza, 445 Hamilton Avenue - Suite 1210, White Plains, NY 10601, (ii) Icahn Master, Icahn Master II and Icahn Master III is c/o Walkers SPV Limited, P.O. Box 908GT, 87 Mary Street, George Town, Grand Cayman, Cayman Islands, and (iii) Mr. Icahn is c/o Icahn Associates Corp., 767 Fifth Avenue, 47th Floor, New York, NY 10153. Barberry is the sole member of Hopper, which is the general partner of High River. Icahn Offshore is the general partner of each of Icahn Master, Icahn Master II and Icahn Master III. Icahn Onshore is the general partner of Icahn Partners. Icahn Capital is the general partner of each of Icahn Offshore and Icahn Onshore. Icahn Enterprises Holdings is the sole member of IPH, which is the general partner of Icahn Capital. Beckton is the sole stockholder of Icahn Enterprises GP, which is the general partner of Icahn Enterprises Holdings. Carl C. Icahn is the sole stockholder of each of Barberry and Beckton. As such, Mr. Icahn is in a position indirectly to determine the investment and voting decisions made by each of the Reporting Persons. In addition, Mr. Icahn is the indirect holder of approximately 92.3% of the outstanding depositary units representing limited partnership interests in Icahn Enterprises L.P. ("Icahn Enterprises"). Icahn Enterprises GP is the general partner of Icahn Enterprises, which is the sole limited partner of Icahn Enterprises Holdings. Each of High River and Barberry is primarily engaged in the business of investing in securities. Hopper is primarily engaged in the business of serving as the general partner of High River. Each of Icahn Master, Icahn Master II, Icahn Master III and Icahn Partners is primarily engaged in the business of investing in securities. Icahn Offshore is primarily engaged in the business of serving as the general partner of each of Icahn Master, Icahn Master II and Icahn Master III. Icahn Onshore is primarily engaged in the business of serving as the general partner of Icahn Partners. Icahn Capital is primarily engaged in the business of serving as the general partner of each of Icahn Offshore and Icahn Onshore. IPH is primarily engaged in the business of serving as the general partner of Icahn Capital. Icahn Enterprises Holdings is primarily engaged in the business of holding direct or indirect interests in various operating businesses. Icahn Enterprises GP is primarily engaged in the business of serving as the general partner of each of Icahn Enterprises and Icahn Enterprises Holdings. Beckton is primarily engaged in the business of holding the capital stock of Icahn Enterprises GP. Carl C. Icahn's present principal occupation or employment is serving as (i) Chief Executive Officer of Icahn Capital LP, a wholly owned subsidiary of Icahn Enterprises, through which Mr. Icahn manages various private investment funds, including Icahn Partners, Icahn Master, Icahn Master II and Icahn Master III, (ii) Chairman of the Board of Icahn Enterprises GP, the general partner of Icahn Enterprises, a New York Stock Exchange listed diversified holding company engaged in a variety of businesses, including investment management, metals, real estate and home fashion, and (iii) Chairman of the Board and a director of Starfire Holding Corporation ("Starfire"), a holding company engaged in the business of investing in and/or holding securities of various entities, and as Chairman of the Board and a director of various of Starfire's subsidiaries. The name, citizenship, present principal occupation or employment and business address of each director and executive officer of the Reporting Persons are set forth in Schedule A attached hereto. None of the Reporting Persons nor any manager or executive officer of the Reporting Persons, has, during the past five years, (a) been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors), or (b) been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting, or mandating activities subject to, Federal or State securities laws or a finding of any violation with respect to such laws. Item 3. Source and Amount of Funds or Other Consideration The Reporting Persons hold, in the aggregate, 7,318,823 Shares. The aggregate purchase price of the Shares purchased by the Reporting Persons collectively was $65,332,001 (including commissions). The source of funding for the purchase of these Shares was the general working capital of the respective purchasers. The Shares are held by the Reporting Persons in margin accounts together with other securities. Such margin accounts may from time to time have debit balances. Part of the purchase price of the Shares purchased by the Reporting Persons was obtained through margin borrowing. As of the close of business on May 26, 2010, the indebtedness of (i) High River's margin account was approximately $397,874,408, (ii) Icahn Partners' margin account was approximately $135,664,638, (iii) Icahn Master's margin account was approximately $190,984,422, (iv) Icahn Master II's margin account was approximately $53,667,537, and (v) Icahn Master III's margin account was approximately $27,580,005. Item 4. Purpose of Transaction The Reporting Persons acquired the Shares in the belief that the Shares were undervalued. The Reporting Persons intend to seek to have conversations with management of the Issuer to discuss the business and operations of the Issuer and the maximization of shareholder value. The Reporting Persons may, from time to time and at any time, acquire additional Shares and/or other equity, debt, notes, instruments or other securities of the Issuer or its subsidiaries (collectively, "Securities") in the open market or otherwise. The Reporting Persons reserve the right to dispose of any or all of their Securities in the open market or otherwise, at any time and from time to time, and to engage in any hedging or similar transactions with respect to the Securities. Item 5. Interest in Securities of the Issuer (a) The Reporting Persons may be deemed to beneficially own, in the aggregate, 7,318,823 Shares, representing approximately 6.86% of the Issuer's outstanding Shares (based upon the 106,690,195 Shares stated to be outstanding as of May 3, 2010 by the Issuer in the Issuer's preliminary proxy statement filed with the Securities and Exchange Commission on May 5, 2010). (b) High River has sole voting power and sole dispositive power with regard to 1,463,764 Shares. Each of Hopper, Barberry and Mr. Icahn has shared voting power and shared dispositive power with regard to such Shares. Icahn Master has sole voting power and sole dispositive power with regard to 2,512,189 Shares. Each of Icahn Offshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton and Mr. Icahn has shared voting power and shared dispositive power with regard to such Shares. Icahn Master II has sole voting power and sole dispositive power with regard to 879,444 Shares. Each of Icahn Offshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton and Mr. Icahn has shared voting power and shared dispositive power with regard to such Shares. Icahn Master III has sole voting power and sole dispositive power with regard to 331,801 Shares. Each of Icahn Offshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton and Mr. Icahn has shared voting power and shared dispositive power with regard to such Shares. Icahn Partners has sole voting power and sole dispositive power with regard to 2,131,625 Shares. Each of Icahn Onshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton and Mr. Icahn has shared voting power and shared dispositive power with regard to such Shares. Each of Hopper, Barberry and Mr. Icahn, by virtue of their relationships to High River (as disclosed in Item 2), may be deemed to indirectly beneficially own (as that term is defined in Rule 13d-3 under the Act) the Shares which High River directly beneficially owns. Each of Hopper, Barberry and Mr. Icahn disclaims beneficial ownership of such Shares for all other purposes. Each of Icahn Offshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton and Mr. Icahn, by virtue of their relationships to each of Icahn Master, Icahn Master II and Icahn Master III (as disclosed in Item 2), may be deemed to indirectly beneficially own (as that term is defined in Rule 13d-3 under the Act) the Shares which each of Icahn Master, Icahn Master II and Icahn Master III directly beneficially owns. Each of Icahn Offshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton and Mr. Icahn disclaims beneficial ownership of such Shares for all other purposes. Each of Icahn Onshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton and Mr. Icahn, by virtue of their relationships to Icahn Partners (as disclosed in Item 2), may be deemed to indirectly beneficially own (as that term is defined in Rule 13d-3 under the Act) the Shares which Icahn Partners directly beneficially owns. Each of Icahn Onshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton and Mr. Icahn disclaims beneficial ownership of such Shares for all other purposes. (c) The following table sets forth all transactions with respect to Shares effected during the past sixty (60) days by any of the Reporting Persons. Except as otherwise noted below, all such transactions were purchases of Shares effected in the open market, and the table includes commissions paid in per share prices. Name of Date No. of Purchase Reporting of Shares Price Per Person Transaction Purchased Share - --------- ----------- --------- --------- High River 04/07/2010 56,020 8.23 High River 04/08/2010 27,880 8.26 High River 04/09/2010 80,000 8.59 High River 04/12/2010 29,640 8.99 High River 04/13/2010 60,000 9.20 High River 04/14/2010 66,800 9.46 High River 04/15/2010 20,800 9.45 High River 04/16/2010 40,000 9.33 High River 04/19/2010 27,860 9.32 High River 04/20/2010 12,820 9.39 High River 04/21/2010 28,840 9.41 High River 04/22/2010 70,000 9.34 High River 04/23/2010 23,040 9.44 High River 04/26/2010 37,140 9.51 High River 04/27/2010 44,740 9.23 High River 04/28/2010 31,000 9.06 High River 04/29/2010 39,520 9.30 High River 04/30/2010 35,240 9.14 High River 05/03/2010 20,000 9.20 High River 05/04/2010 40,000 8.88 High River 05/05/2010 36,860 8.79 High River 05/06/2010 34,820 8.48 High River 05/07/2010 40,000 8.17 High River 05/10/2010 25,820 8.57 High River 05/11/2010 32,400 8.64 High River 05/12/2010 34,500 8.80 High River 05/13/2010 38,840 9.12 High River 05/14/2010 26,240 8.93 High River 05/17/2010 43,387 8.92 High River 05/18/2010 56,400 9.00 High River 05/19/2010 57,520 8.96 High River 05/20/2010 60,000 8.70 High River 05/21/2010 41,720 8.61 High River 05/24/2010 32,660 8.58 High River 05/25/2010 38,120 8.30 High River 05/26/2010 34,102 8.62 High River 05/27/2010 39,035 8.92 Icahn Partners 04/07/2010 82,225 8.23 Icahn Partners 04/08/2010 40,921 8.26 Icahn Partners 04/09/2010 117,422 8.59 Icahn Partners 04/12/2010 43,505 8.99 Icahn Partners 04/13/2010 88,067 9.20 Icahn Partners 04/14/2010 98,048 9.46 Icahn Partners 04/15/2010 30,529 9.45 Icahn Partners 04/16/2010 58,710 9.33 Icahn Partners 04/19/2010 40,892 9.32 Icahn Partners 04/20/2010 18,817 9.39 Icahn Partners 04/21/2010 42,331 9.41 Icahn Partners 04/22/2010 102,744 9.34 Icahn Partners 04/23/2010 33,817 9.44 Icahn Partners 04/26/2010 54,514 9.51 Icahn Partners 04/27/2010 65,668 9.23 Icahn Partners 04/28/2010 45,501 9.06 Icahn Partners 04/29/2010 58,007 9.30 Icahn Partners 04/30/2010 51,724 9.14 Icahn Partners 05/03/2010 20,124 9.20 Icahn Partners 05/04/2010 58,832 8.88 Icahn Partners 05/05/2010 53,678 8.79 Icahn Partners 05/06/2010 50,707 8.48 Icahn Partners 05/07/2010 58,251 8.17 Icahn Partners 05/10/2010 37,600 8.57 Icahn Partners 05/11/2010 47,183 8.64 Icahn Partners 05/12/2010 50,241 8.80 Icahn Partners 05/13/2010 56,561 9.12 Icahn Partners 05/14/2010 38,213 8.93 Icahn Partners 05/17/2010 63,182 8.92 Icahn Partners 05/18/2010 82,134 9.00 Icahn Partners 05/19/2010 83,764 8.96 Icahn Partners 05/20/2010 87,375 8.70 Icahn Partners 05/21/2010 60,755 8.61 Icahn Partners 05/24/2010 47,563 8.58 Icahn Partners 05/25/2010 55,512 8.30 Icahn Partners 05/26/2010 49,662 8.62 Icahn Partners 05/27/2010 56,846 8.92 Icahn Master 04/07/2010 94,135 8.23 Icahn Master 04/08/2010 46,848 8.26 Icahn Master 04/09/2010 134,430 8.59 Icahn Master 04/12/2010 49,806 8.99 Icahn Master 04/13/2010 100,823 9.20 Icahn Master 04/14/2010 112,249 9.46 Icahn Master 04/15/2010 34,952 9.45 Icahn Master 04/16/2010 67,215 9.33 Icahn Master 04/19/2010 46,815 9.32 Icahn Master 04/20/2010 21,543 9.39 Icahn Master 04/21/2010 48,462 9.41 Icahn Master 04/22/2010 117,626 9.34 Icahn Master 04/23/2010 38,716 9.44 Icahn Master 04/26/2010 62,409 9.51 Icahn Master 04/27/2010 75,179 9.23 Icahn Master 04/28/2010 52,092 9.06 Icahn Master 04/29/2010 66,408 9.30 Icahn Master 04/30/2010 59,217 9.14 Icahn Master 05/03/2010 59,876 9.20 Icahn Master 05/04/2010 69,337 8.88 Icahn Master 05/05/2010 63,261 8.79 Icahn Master 05/06/2010 59,760 8.48 Icahn Master 05/07/2010 68,650 8.17 Icahn Master 05/10/2010 44,313 8.57 Icahn Master 05/11/2010 55,607 8.64 Icahn Master 05/12/2010 59,210 8.80 Icahn Master 05/13/2010 66,660 9.12 Icahn Master 05/14/2010 45,034 8.93 Icahn Master 05/17/2010 74,463 8.92 Icahn Master 05/18/2010 96,796 9.00 Icahn Master 05/19/2010 98,719 8.96 Icahn Master 05/20/2010 102,975 8.70 Icahn Master 05/21/2010 71,603 8.61 Icahn Master 05/24/2010 56,052 8.58 Icahn Master 05/25/2010 65,424 8.30 Icahn Master 05/26/2010 58,529 8.62 Icahn Master 05/27/2010 66,995 8.92 Icahn Master II 04/07/2010 34,635 8.23 Icahn Master II 04/08/2010 17,237 8.26 Icahn Master II 04/09/2010 49,460 8.59 Icahn Master II 04/12/2010 18,326 8.99 Icahn Master II 04/13/2010 37,095 9.20 Icahn Master II 04/14/2010 41,299 9.46 Icahn Master II 04/15/2010 12,861 9.45 Icahn Master II 04/16/2010 24,730 9.33 Icahn Master II 04/19/2010 17,225 9.32 Icahn Master II 04/20/2010 7,926 9.39 Icahn Master II 04/21/2010 17,830 9.41 Icahn Master II 04/22/2010 43,279 9.34 Icahn Master II 04/23/2010 14,245 9.44 Icahn Master II 04/26/2010 22,961 9.51 Icahn Master II 04/27/2010 27,662 9.23 Icahn Master II 04/28/2010 19,166 9.06 Icahn Master II 04/29/2010 24,433 9.30 Icahn Master II 04/30/2010 21,787 9.14 Icahn Master II 05/04/2010 23,288 8.88 Icahn Master II 05/05/2010 22,146 8.79 Icahn Master II 05/06/2010 20,920 8.48 Icahn Master II 05/07/2010 24,032 8.17 Icahn Master II 05/10/2010 15,514 8.57 Icahn Master II 05/11/2010 19,466 8.64 Icahn Master II 05/12/2010 20,729 8.80 Icahn Master II 05/13/2010 23,335 9.12 Icahn Master II 05/14/2010 15,764 8.93 Icahn Master II 05/17/2010 26,068 8.92 Icahn Master II 05/18/2010 33,885 9.00 Icahn Master II 05/19/2010 34,559 8.96 Icahn Master II 05/20/2010 36,048 8.70 Icahn Master II 05/21/2010 25,067 8.61 Icahn Master II 05/24/2010 8,641 8.30 Icahn Master II 05/25/2010 19,622 8.58 Icahn Master II 05/26/2010 20,489 8.62 Icahn Master II 05/27/2010 23,452 8.92 Icahn Master III 04/07/2010 13,085 8.23 Icahn Master III 04/08/2010 6,514 8.26 Icahn Master III 04/09/2010 18,688 8.59 Icahn Master III 04/12/2010 6,923 8.99 Icahn Master III 04/13/2010 14,015 9.20 Icahn Master III 04/14/2010 15,604 9.46 Icahn Master III 04/15/2010 4,858 9.45 Icahn Master III 04/16/2010 9,345 9.33 Icahn Master III 04/19/2010 6,508 9.32 Icahn Master III 04/20/2010 2,994 9.39 Icahn Master III 04/21/2010 6,737 9.41 Icahn Master III 04/22/2010 16,351 9.34 Icahn Master III 04/23/2010 5,382 9.44 Icahn Master III 04/26/2010 8,676 9.51 Icahn Master III 04/27/2010 10,451 9.23 Icahn Master III 04/28/2010 7,241 9.06 Icahn Master III 04/29/2010 9,232 9.30 Icahn Master III 04/30/2010 8,232 9.14 Icahn Master III 05/04/2010 8,543 8.88 Icahn Master III 05/05/2010 8,355 8.79 Icahn Master III 05/06/2010 7,893 8.48 Icahn Master III 05/07/2010 9,067 8.17 Icahn Master III 05/10/2010 5,853 8.57 Icahn Master III 05/11/2010 7,344 8.64 Icahn Master III 05/12/2010 7,820 8.80 Icahn Master III 05/13/2010 8,804 9.12 Icahn Master III 05/14/2010 5,949 8.93 Icahn Master III 05/17/2010 9,835 8.92 Icahn Master III 05/18/2010 12,785 9.00 Icahn Master III 05/19/2010 13,038 8.96 Icahn Master III 05/20/2010 13,602 8.70 Icahn Master III 05/21/2010 9,455 8.61 Icahn Master III 05/24/2010 7,403 8.58 Icahn Master III 05/25/2010 8,641 8.30 Icahn Master III 05/26/2010 7,730 8.62 Icahn Master III 05/27/2010 8,848 8.92 Item 6. Contracts, Arrangements, Understandings or Relationship with Respect to Securities of the Issuer Except as otherwise described herein, there are no contracts, arrangements, understandings or relationships (legal or otherwise) among the persons named in Item 2 and between such persons and any person with respect to any securities of the Issuer, including but not limited to transfer or voting of any of the securities, finder's fees, joint ventures, loan or option arrangements, puts or calls, guarantees of profits, division of profits or loss, or the giving or withholding of proxies. Item 7. Material to be Filed as Exhibits 1 Joint Filing Agreement of the Reporting Persons. SIGNATURE After reasonable inquiry and to the best of each of the undersigned knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct. Dated: May 27, 2010 ICAHN PARTNERS MASTER FUND LP ICAHN PARTNERS MASTER FUND II LP ICAHN PARTNERS MASTER FUND III LP ICAHN OFFSHORE LP ICAHN PARTNERS LP ICAHN ONSHORE LP BECKTON CORP. HOPPER INVESTMENTS LLC BARBERRY CORP. HIGH RIVER LIMITED PARTNERSHIP By: Hopper Investments LLC, general partner By: /s/ Edward E. Mattner ------------------------ Name: Edward E. Mattner Title: Authorized Signatory ICAHN CAPITAL LP By: IPH GP LLC, its general partner By: Icahn Enterprises Holdings L.P., its sole member By: Icahn Enterprises G.P. Inc., its general partner IPH GP LLC By: Icahn Enterprises Holdings L.P., its sole member By: Icahn Enterprises G.P. Inc., its general partner ICAHN ENTERPRISES HOLDINGS L.P. By: Icahn Enterprises G.P. Inc., its general partner ICAHN ENTERPRISES G.P. INC. By: /s/ Dominick Ragone --------------------- Name: Dominick Ragone Title: Chief Financial Officer /s/ Carl C. Icahn - -------------------- CARL C. ICAHN [Signature Page of Schedule 13D - Mentor Graphics Corporation] EXHIBIT 1 JOINT FILING AGREEMENT In accordance with Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf of each of them of a statement on Schedule 13D (including amendments thereto) with respect to the Common Stock of Mentor Graphics Corporation and further agree that this Joint Filing Agreement be included as an Exhibit to such joint filings. In evidence thereof, the undersigned, being duly authorized, have executed this Joint Filing Agreement this 27th day of May, 2010. ICAHN PARTNERS MASTER FUND LP ICAHN PARTNERS MASTER FUND II LP ICAHN PARTNERS MASTER FUND III LP ICAHN OFFSHORE LP ICAHN PARTNERS LP ICAHN ONSHORE LP BECKTON CORP. HOPPER INVESTMENTS LLC BARBERRY CORP. HIGH RIVER LIMITED PARTNERSHIP By: Hopper Investments LLC, general partner By: /s/ Edward E. Mattner ------------------------ Name: Edward E. Mattner Title: Authorized Signatory ICAHN CAPITAL LP By: IPH GP LLC, its general partner By: Icahn Enterprises Holdings L.P., its sole member By: Icahn Enterprises G.P. Inc., its general partner IPH GP LLC By: Icahn Enterprises Holdings L.P., its sole member By: Icahn Enterprises G.P. Inc., its general partner ICAHN ENTERPRISES HOLDINGS L.P. By: Icahn Enterprises G.P. Inc., its general partner ICAHN ENTERPRISES G.P. INC. By: /s/ Dominick Ragone --------------------- Name: Dominick Ragone Title: Chief Financial Officer /s/ Carl C. Icahn - -------------------- CARL C. ICAHN [Signature Page of Joint Filing Agreement to Schedule 13D - Mentor Graphics Corporation] SCHEDULE A DIRECTORS AND EXECUTIVE OFFICERS OF THE REPORTING PERSONS The following sets forth the name, position, and principal occupation of each director and executive officer of each of the Reporting Persons. Each such person is a citizen of the United States of America. Except as otherwise indicated, the business address of each director and officer is c/o Icahn Associates Corp., 767 Fifth Avenue, 47th Floor, New York, New York 10153. To the best of the Reporting Persons' knowledge, except as set forth in this statement on Schedule 13D, none of the directors or executive officers of the Reporting Persons own any Shares. ICAHN PARTNERS MASTER FUND LP ICAHN PARTNERS MASTER FUND II LP ICAHN PARTNERS MASTER FUND III LP Name Position - ---- -------- Icahn Offshore LP General Partner Carl Icahn Chief Executive Officer Keith A. Meister Managing Director Vincent J. Intrieri Managing Director Irene March Chief Financial Officer Edward E. Mattner Authorized Signatory Gail Golden Authorized Signatory Dana Witkin Director of Investor Relations Keith Cozza Chief Compliance Officer Anthony Canova Controller ICAHN PARTNERS LP Name Position - ---- -------- Icahn Onshore LP General Partner Carl Icahn Chief Executive Officer Keith A. Meister Managing Director Vincent J. Intrieri Managing Director Irene March Chief Financial Officer Edward E. Mattner Authorized Signatory Gail Golden Authorized Signatory Dana Witkin Director of Investor Relations Keith Cozza Chief Compliance Officer Anthony Canova Controller ICAHN ONSHORE LP ICAHN OFFSHORE LP Name Position - ---- -------- Icahn Capital LP General Partner Carl Icahn Chief Executive Officer Keith A. Meister Managing Director Vincent J. Intrieri Managing Director Irene March Chief Financial Officer Edward E. Mattner Authorized Signatory Gail Golden Authorized Signatory Dana Witkin Director of Investor Relations Keith Cozza Chief Compliance Officer Anthony Canova Controller ICAHN CAPITAL LP Name Position - ---- -------- IPH GP LLC General Partner Carl Icahn Chief Executive Officer Keith A. Meister Managing Director Vincent J. Intrieri Managing Director Irene March Chief Financial Officer Edward E. Mattner Authorized Signatory Gail Golden Authorized Signatory Dana Witkin Director of Investor Relations Keith Cozza Chief Compliance Officer Anthony Canova Controller IPH GP LLC Name Position - ---- -------- Icahn Enterprises Sole Member Holdings L.P. Carl Icahn Chief Executive Officer Keith A. Meister Managing Director Vincent J. Intrieri Managing Director Irene March Chief Financial Officer Edward E. Mattner Authorized Signatory Gail Golden Authorized Signatory Dana Witkin Director of Investor Relations Keith Cozza Chief Compliance Officer Anthony Canova Controller ICAHN ENTERPRISES HOLDINGS L.P. Name Position - ---- -------- Icahn Enterprises General Partner G.P. Inc. ICAHN ENTERPRISES G.P. INC. Name Position - ---- -------- Carl C. Icahn Chairman Keith A. Meister Vice Chairman, Principal Executive Officer Daniel Ninivaggi President William A. Leidesdorf Director Jack G. Wasserman Director James L. Nelson Director Vincent J. Intrieri Director Dominick Ragone Chief Financial Officer Felicia P. Buebel Assistant Secretary Craig Petit Vice President/Taxes BECKTON CORP. Name Position - ---- -------- Carl C. Icahn Chairman of the Board; President Jordan Bleznick Vice President/Taxes Edward E. Mattner Authorized Signatory Keith Cozza Secretary; Treasurer HIGH RIVER LIMITED PARTNERSHIP Name Position - ---- -------- Hopper Investments LLC General Partner HOPPER INVESTMENTS LLC Name Position - ---- -------- Barberry Corp General Partner Edward E. Mattner Authorized Signatory BARBERRY CORP. Name Position - ---- -------- Carl C. Icahn Chairman of the Board; President Gail Golden Vice President; Authorized Signatory Jordan Bleznick Vice President/Taxes Vincent J. Intrieri Vice President; Authorized Signatory Irene March Authorized Signatory Edward E. Mattner Authorized Signatory Keith Cozza Secretary; Treasurer