EXHIBIT 10.58

FIRST AMENDMENT TO

CONSULTING AGREEMENT

THIS FIRST AMENDMENT (“First Amendment”) effective as of December 13, 2005 (the
“Effective Date”), to the Consulting Agreement dated June 30, 2005, is entered
into by and between MSC.Software Corporation, a Delaware corporation (“MSC”) and
Kenneth D. Blakely, an individual (“Blakely”).

WHEREAS, Blakely was previously employed as the Vice President of Special
Projects for MSC;

WHEREAS, Blakely and MSC mutually agreed to terminate Blakely employment
relationship with MSC pursuant to an Employment Separation and General Release
Agreement dated June 30, 2005 (the “Separation Agreement”); and

WHEREAS, MSC and Blakely thereafter entered into that certain Consulting
Agreement dated June 30, 2005 for the purpose of Blakely rendering consulting
services from time to time to MSC (the “Agreement”); and

WHEREAS, MSC and Blakely desire to amend the Agreement in order to extend the
Consulting Term as that term is defined in the Agreement, from December 31, 2005
through and including March 31, 2006;

NOW, THEREFORE, in consideration of the covenants contained herein, the above
recitals and other good and valuable consideration, the receipt and sufficiency
of which are hereby acknowledged, the parties agree as follows:

 

  1. The first sentence of Section I of the Agreement shall be amended so as to
read as follows:

“I. Engagement. MSC hereby engages Blakely and Blakely hereby accepts such
engagement, upon the terms and conditions hereinafter set forth, for the period
commencing July 1, 2005 and ending on March 31, 2006 unless earlier terminated
as provided in Section IV herein (such period is referred to as the “Consulting
Term”).”

 

  2. Consistent with the extension of the Consulting Term as referenced above,
wherever the Agreement refers to the ending date of December 31, 2005, that date
shall be extended through March 31, 2006.

For purposes of clarity, with regard to the 2000 Executive Cash or Stock Bonus
Plan (the “Plan”) under which Blakely has scheduled deferred bonus payments, and
consistent with the rules of the Plan and MSC’s policy, Blakely shall be paid
any amounts previously awarded under the Plan on or about March 31, 2006,
co-terminus with the end of the Consulting Term, which payments shall not imply
a bonus for the year ending December 31, 2005.

This Amendment shall in no way affect the terms of the Separation Agreement
between the parties, and any amendments thereto including, without limitation,
the treatment of Blakely’s stock options as set forth in Section XI of the
Separation Agreement.

Except as expressly modified by this First Amendment, the Agreement shall be and
remain in full force and effect in accordance with its terms, and shall
constitute the legal, valid, binding, and enforceable obligations of MSC and
Blakely. This First Amendment, including the Agreement and any attachments
thereto, is the complete agreement of the parties and supersedes any prior
agreements or representations, whether oral or written, with respect thereto. In
the event of a conflict between the terms of this First Amendment and the
Agreement, the terms of the First Amendment shall govern as to the subject
matter referenced herein.

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[Signatures intentionally appear on the following page.]

IN WITNESS WHEREOF, the parties have signed this First Amendment on the dates
indicated below.

 

MSC.Software Corporation

a Delaware Corporation

   

Kenneth D. Blakely

an Individual

By:   /s/    WILLIAM J. WEYAND    

By:

  /s/    KENNETH D. BLAKELY Name:   William J. Weyand     Name:   Kenneth D.
Blakely Title:   Chief Executive Officer     Title:   Blakely Date:   December
23, 2005     Date:   December 23, 2005