POS EX

As filed with the Securities and Exchange Commission on August 18, 2009

Registration No. 333-159631

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

POST-EFFECTIVE AMENDMENT NO. 1

TO

FORM S-4

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

MENTOR GRAPHICS CORPORATION

(Exact name of registrant as specified in its charter)

OREGON	7373	93-0786033
(State or other jurisdiction of incorporation or organization)	(Primary Standard Industrial Classification Code Number)	(I.R.S. Employer Identification Number)

8005 SW Boeckman Road

Wilsonville, Oregon 97070-7777

(503) 685-7000

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

DEAN M. FREED

Vice President and General Counsel

Mentor Graphics Corporation

8005 SW Boeckman Road

Wilsonville, Oregon 97070-7777

(503) 685-7000

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

Copies to:

Christopher L. Kaufman, Esq. Jamie K. Leigh, Esq. Latham & Watkins LLP 140 Scott Drive Menlo Park, California 94025 (650) 328-4600 Stanton D. Wong, Esq. Pillsbury Winthrop Shaw Pittman LLP 50 Fremont Street San Francisco, California 94105 (415) 983-1000

Approximate date of commencement of proposed sale of the securities to the public: As soon as practicable after the effectiveness of this registration statement and the satisfaction or waiver of all other conditions under the merger agreement described herein.

If the securities being registered on this form are being offered in connection with the formation of a holding company and there is compliance with General Instruction G, 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, check the following box and list the Securities Act registration statement number of the earlier effective registration statement number for the same offering.  ¨

If this form is a post-effective amendment filed pursuant to Rule 462(d) 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.  x 333-159631

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 the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer  x	Accelerated filer  ¨
Non-accelerated filer  ¨ (Do not check if a smaller reporting company)	Smaller reporting company  ¨

If applicable, place an X in the box to designate the appropriate rule provision relied upon in conducting this transaction:

Exchange Act Rule 13e-4(i) (Cross-Border Issuer Tender Offer)  ¨

Exchange Act Rule 14d-1(d) (Cross-Border Third-Party Tender Offer)  ¨

This Registration Statement shall become effective upon filing with the Securities and Exchange Commission in accordance with Rule 462(d) under the Securities Act of 1933, as amended.

Explanatory Note

This Post-effective Amendment No. 1 to Mentor Graphics Corporation’s Registration Statement on Form S-4 (Registration No. 333-159631) originally filed with the Securities and Exchange Commission on June 1, 2009, as amended by Amendment No. 1, filed July 1, 2009, as amended by Amendment No. 2, filed July 13, 2009, and as amended by Amendment No. 3, filed July 14, 2009, is being filed for the sole purpose of amending the exhibit index to include Exhibits No. 8.3 and 23.6 filed herewith. No changes have been made to Part I or Part II of the Registration Statement other than Item 21(a) of Part II as set forth below.

ITEM 21. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES

(a) Exhibits

Exhibit Number	Exhibit Description
2.1	Agreement and Plan of Merger, dated as of May 6, 2009, by and among the Registrant, Fulcrum Acquisition Corporation and LogicVision, Inc. (included as Annex A to the proxy statement/prospectus).*
3.1	1987 Restated Articles of Incorporation of the Registrant, as amended (incorporated by reference to Exhibit 3A to the Registrant’s Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2004 (SEC File No. 000-13442)).
3.2	Bylaws of the Registrant (incorporated by reference to Exhibit 3C to the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2000 (SEC File No. 000-13442)).
4.1	Indenture, dated as of August 6, 2003, between the Registrant and Wilmington Trust Company related to Floating Rate Convertible Subordinated Debentures due 2023 (incorporated by reference to Exhibit 4.2 to the Registrant’s Registration Statement on Form S-3 filed on October 22, 2003 (SEC File No. 333-109885)).
4.2	Registration Rights Agreement, dated as of August 6, 2003, between the Registrant and Merrill Lynch, Pierce, Fenner & Smith Incorporated, Banc of America Securities LLC, Fleet Securities, Inc., and Needham & Company, Inc. (incorporated by reference to Exhibit 4.4 to the Registrant’s Registration Statement on Form S-3 filed on October 22, 2003 (SEC File No. 333-109885)).
4.3	Indenture, dated as of March 3, 2006, between the Registrant and Wilmington Trust Company related to 6.25% Convertible Subordinated Debentures due 2026 (incorporated by reference to Exhibit 4.1 to the Registrant’s Current Report on Form 8-K filed on March 9, 2006 (SEC File No. 000-13442)).
4.4	Registration Rights Agreement, dated as of March 3, 2006, between the Registrant and Merrill Lynch, Pierce Fenner & Smith Incorporated, Banc of America Securities LLC and UBS Securities LLC (incorporated by reference to Exhibit 10.1 to the Registrant’s Current Report on Form 8-K filed on March 9, 2006 (SEC File No. 000-13442)).
5.1†	Legal opinion of Dean M. Freed.
8.1†	Tax opinion of Latham & Watkins LLP.
8.2†	Tax opinion of Pillsbury Winthrop Shaw Pittman LLP.
8.3	Tax opinion of Pillsbury Winthrop Shaw Pittman LLP.
10.1	Form of Support Agreement between the Registrant and certain stockholders of LogicVision, Inc., dated as of May 6, 2009 (included as Annex B to the proxy statement/prospectus).
21.1†	Subsidiaries of the Registrant.
23.1†	Consent of Dean M. Freed (included in Exhibit 5.1).
23.2†	Consent of Latham & Watkins LLP (included in Exhibit 8.1).
23.3†	Consent of Pillsbury Winthrop Shaw Pittman LLP (included in Exhibit 8.2).
23.4†	Consent of KPMG LLP, independent registered public accounting firm.
23.5†	Consent of Burr, Pilger & Mayer LLP, independent registered public accounting firm.
23.6	Consent of Pillsbury Winthrop Shaw Pittman LLP (included in Exhibit 8.3).
24.1	Power of Attorney (see pages II-5 to II-6 of the original filing of this Form S-4).
99.1†	Form of Proxy of LogicVision, Inc.
99.2	Opinion of Needham & Company, LLC, financial advisor to LogicVision, Inc. (included as Annex C to the proxy statement/prospectus).
99.3†	Consent of Needham & Company, LLC.

* Schedules have been omitted pursuant to Item 601(b)(2) of Regulation S-K. Mentor Graphics hereby undertakes to furnish supplementally copies of any of the omitted schedules upon request by the SEC.

† Previously filed.

II-1

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Wilsonville, State of Oregon, on August 18, 2009.

MENTOR GRAPHICS CORPORATION
By:	/S/    DEAN M. FREED
Name:	Dean M. Freed
Title:	Vice President and General Counsel

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
* Walden C. Rhines	Chairman of the Board and Chief Executive Officer (Principal Executive Officer)	August 18, 2009
* Gregory K. Hinckley	Director, President and Chief Financial Officer (Principal Financial and Accounting Officer)	August 18, 2009
* Sir Peter Bonfield	Director	August 18, 2009
Marsha B. Congdon	Director
* James R. Fiebiger	Director	August 18, 2009
* Kevin C. McDonough	Director	August 18, 2009
* Patrick B. McManus	Director	August 18, 2009
* Fontaine K. Richardson	Director	August 18, 2009

*By:	/S/    DEAN M. FREED
	Dean M. Freed (Attorney-in-fact)

EXHIBIT INDEX

Exhibit Number	Exhibit Description
2.1	Agreement and Plan of Merger, dated as of May 6, 2009, by and among the Registrant, Fulcrum Acquisition Corporation and LogicVision, Inc. (included as Annex A to the proxy statement/prospectus).*
3.1	1987 Restated Articles of Incorporation of the Registrant, as amended (incorporated by reference to Exhibit 3A to the Registrant’s Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2004 (SEC File No. 000-13442)).
3.2	Bylaws of the Registrant (incorporated by reference to Exhibit 3C to the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2000 (SEC File No. 000-13442)).
4.1	Indenture, dated as of August 6, 2003, between the Registrant and Wilmington Trust Company related to Floating Rate Convertible Subordinated Debentures due 2023 (incorporated by reference to Exhibit 4.2 to the Registrant’s Registration Statement on Form S-3 filed on October 22, 2003 (SEC File No. 333-109885)).
4.2	Registration Rights Agreement, dated as of August 6, 2003, between the Registrant and Merrill Lynch, Pierce, Fenner & Smith Incorporated, Banc of America Securities LLC, Fleet Securities, Inc., and Needham & Company, Inc. (incorporated by reference to Exhibit 4.4 to the Registrant’s Registration Statement on Form S-3 filed on October 22, 2003 (SEC File No. 333-109885)).
4.3	Indenture, dated as of March 3, 2006, between the Registrant and Wilmington Trust Company related to 6.25% Convertible Subordinated Debentures due 2026 (incorporated by reference to Exhibit 4.1 to the Registrant’s Current Report on Form 8-K filed on March 9, 2006 (SEC File No. 000-13442)).
4.4	Registration Rights Agreement, dated as of March 3, 2006, between the Registrant and Merrill Lynch, Pierce Fenner & Smith Incorporated, Banc of America Securities LLC and UBS Securities LLC (incorporated by reference to Exhibit 10.1 to the Registrant’s Current Report on Form 8-K filed on March 9, 2006 (SEC File No. 000-13442)).
5.1†	Legal opinion of Dean M. Freed.
8.1†	Tax opinion of Latham & Watkins LLP.
8.2†	Tax opinion of Pillsbury Winthrop Shaw Pittman LLP.
8.3	Tax opinion of Pillsbury Winthrop Shaw Pittman LLP.
10.1	Form of Support Agreement between the Registrant and certain stockholders of LogicVision, Inc., dated as of May 6, 2009 (included as Annex B to the proxy statement/prospectus).
21.1†	Subsidiaries of the Registrant.
23.1†	Consent of Dean M. Freed (included in Exhibit 5.1).
23.2†	Consent of Latham & Watkins LLP (included in Exhibit 8.1).
23.3†	Consent of Pillsbury Winthrop Shaw Pittman LLP (included in Exhibit 8.2).
23.4†	Consent of KPMG LLP, independent registered public accounting firm.
23.5†	Consent of Burr, Pilger & Mayer LLP, independent registered public accounting firm.
23.6	Consent of Pillsbury Winthrop Shaw Pittman LLP (included in Exhibit 8.3).
24.1	Power of Attorney (see pages II-5 to II-6 of the original filing of this Form S-4).
99.1†	Form of Proxy of LogicVision, Inc.
99.2	Opinion of Needham & Company, LLC, financial advisor to LogicVision, Inc. (included as Annex C to the proxy statement/prospectus).
99.3†	Consent of Needham & Company, LLC.

* Schedules have been omitted pursuant to Item 601(b)(2) of Regulation S-K. Mentor Graphics hereby undertakes to furnish supplementally copies of any of the omitted schedules upon request by the SEC.

† Previously filed.

EX-8.3

Exhibit 8.3

August 18, 2009

LogicVision, Inc.

25 Metro Drive, Third Floor

San Jose, California 95110

Ladies and Gentlemen:

You have asked for our opinion as to certain federal income tax consequences of the proposed plan of reorganization that would result in the merger (the “Merger”) of Fulcrum Acquisition Corporation (“Merger Subsidiary”), a Delaware corporation and wholly owned subsidiary of Mentor Graphics Corporation (“Parent”), an Oregon corporation, with and into LogicVision, Inc. (the “Company”), a Delaware corporation. The proposed plan (the “Plan”) is set forth in the Agreement and Plan of Merger (the “Agreement”), dated as of May 6, 2009, among Parent, Merger Subsidiary and the Company. This opinion is being delivered in accordance with Section 6.11(c) of the Agreement.

We understand, and the opinion rendered herein assumes, that the facts surrounding the Merger are as follows:

The authorized capital stock of the Company consists of 50 million shares of common stock, $0.0001 par value per share (the “Company Common Stock”), and 5 million shares of preferred stock, $0.0001 par value per share, of which 250,000 shares are designated as Series A Participating Preferred Stock. As of May 4, 2009, 9,473,572 shares of Company Common Stock were issued and outstanding and no shares of Company preferred stock were issued or outstanding. Company Common Stock is traded on the NASDAQ Capital Market.

The authorized capital stock of Parent consists of 200 million shares of common stock, no par value (the “Parent Common Stock”), and 1.2 million shares of incentive stock. Parent Common Stock is traded on the NASDAQ Global Select Market.

Merger Subsidiary was formed in order to effect the Plan and Merger, which is being undertaken by Parent, Company and Merger Subsidiary pursuant to the terms of the Agreement for the reasons specified in the Proxy Statement/Prospectus submitted to the stockholders of the Company in connection with the solicitation of their approval of the Merger (the “Proxy Statement/Prospectus”). Parent owns all of the issued and outstanding shares of common stock of Merger Subsidiary, the only issued and outstanding capital stock of Merger Subsidiary.

Under the Plan, Merger Subsidiary will merge with and into the Company in accordance with Delaware law. Upon the effectiveness of the Merger (the “Effective Time”), the following will occur:

1. The Company will be the surviving corporation, and the separate existence of Merger Subsidiary will cease.

2. Each issued and outstanding share of Merger Subsidiary common stock held by Parent will be converted into one share of common stock of the Company, the corporation surviving the Merger.

3. Each share of Company Common Stock that is issued and outstanding immediately prior to the Effective Time will be converted into the right to receive 0.2006 shares of Parent Common Stock.

4. No fractional shares of Parent Common Stock will be issued in the Merger. Each Company stockholder otherwise entitled to a fractional share of Parent Common Stock will receive instead an amount of cash equal to such fraction multiplied by the closing sale price of a share of Parent Common Stock on the NASDAQ Global Select Market on the trading day immediately preceding the Effective Time.

Under Delaware law, Company stockholders are not entitled to appraisal or dissenter’s rights in connection with the Merger.

LogicVision, Inc.

August 18, 2009

Page 2

For purposes of rendering this opinion we have examined and are relying upon (without any independent investigation or review) the truth, correctness and completeness at all relevant times of the statements, covenants, representations and warranties contained in the Agreement, letters dated [Closing Date] delivered to us by the Company and by Parent and Merger Subsidiary containing their respective tax-related representations (the “Tax Representation Letters”), the Proxy Statement/Prospectus and such other instruments and documents as we have deemed necessary.

Further, for purposes of rendering this opinion we have made the following assumptions (without any independent investigation or review):

(a) Original documents submitted to us (including signatures) are authentic, documents submitted to us as copies conform to the original documents and all such documents either have been or will be by the Effective Time duly and validly executed and delivered where such execution and delivery are prerequisites to effectiveness;

(b) All representations, warranties and statements made or agreed to by the Company, Parent and Merger Subsidiary by their respective managements, officers and directors in connection with the Merger, including but not limited to those set forth in the Agreement, the Tax Representation Letters and the Proxy Statement/Prospectus, are true, correct and complete at all relevant times;

(c) All covenants contained in the Agreement will be performed without waiver or breach of any material provisions; and

(d) Any representation or statement made “to the best knowledge” or similarly qualified is correct without such qualification.

Based solely on the information, understandings and assumptions and subject to the limitations contained herein, we are in the opinion that the Merger will constitute a reorganization within the meaning of Internal Revenue Code section 368(a).

The opinion expressed herein is based upon laws, judicial decisions and administrative regulations, rulings and practice, all as in effect on the date hereof and all of which are subject to change, either on a prospective or retroactive basis. New developments in any such administrative matters, court decisions, legislative changes, or changes in the facts, assumptions or other information upon which our opinion is based may have an adverse effect on the legal or tax consequences described herein, and we do not accept any responsibility for updating or revising our opinion in consequence of any such new development or changes. No opinion is expressed about the federal tax treatment of the proposed Merger under other provisions of the Internal Revenue Code, about the federal income tax treatment of any conditions existing at the time of, or effects resulting from, the proposed Merger that are not specifically covered by the above opinion, nor about any tax effects of the proposed Merger other than its status as a reorganization for federal income tax purposes. Additional issues may exist that could affect the federal tax treatment of the Merger and this opinion does not consider or provide a conclusion with respect to any such additional issues. With respect to any significant federal tax issues outside the limited scope of this opinion, this opinion was not written and cannot be used by the recipient or any other party for the purpose of avoiding penalties that may be imposed under the Internal Revenue Code on the recipient or such other party.

We hereby consent to the filing of this opinion with the Registration Statement (the “Registration Statement”) on Form S-4 filed by Parent with the Securities and Exchange Commission that includes the Proxy Statement/Prospectus and to the use of our name in the Registration Statement and in the Proxy Statement/Prospectus. In giving this consent, we do not thereby admit that we are within the category of persons whose consent is required under Section 7 of the Securities Act of 1933 or the rules and regulations of the Securities and Exchange Commission promulgated thereunder.

Very truly yours,

/s/ Pillsbury Winthrop Shaw Pittman LLP