Exhibit 10
AMENDMENT NO. 2
TO THE SECOND AMENDED AND RESTATED
LIMITED LIABILITY COMPANY AGREEMENT OF
CALAMOS HOLDINGS LLC
AMENDMENT NO. 2, dated as of May 18, 2006 (“Amendment No. 2”), to the Second
Amended and Restated Limited Liability Company Agreement of Calamos Holdings LLC
dated as of November 2, 2004 and amended December 6, 2004 (the “Limited
Liability Company Agreement”), by and among Calamos Asset Management, Inc., a
Delaware Corporation, Calamos Family Partners, Inc., a Delaware Corporation, and
John P. Calamos, Sr., an individual.
WHEREAS, pursuant to Section 11.12(a) of the Limited Liability Company
Agreement, the parties hereto desire to amend the terms of the Limited Liability
Company Agreement to reflect certain additional understandings.
NOW, THEREFORE, the parties hereto hereby agree as follows:

  1.   Amendment. Section 2.06 of the Limited Liability Company Agreement is
hereby amended to remove “Calamos Capital LLC”.     2.   Reaffirmation. In all
other respects the Limited Liability Company Agreement remains the same and in
full force and effect.     3.   Effective Date. This Amendment No. 2 shall
become effective as of the date first written above (the “Effective Date”). On
and after the Effective Date of this Amendment No. 2, each reference in the
Limited Liability Company Agreement to “this Agreement,” “hereunder,” “hereof,”
or words of like import referring to the Limited Liability Company Agreement
shall mean and be a reference to the Limited Liability Company Agreement as
amended by this Amendment No. 2.     4.   Governing Law. The validity and
construction of this Amendment No. 2 shall be determined and governed in all
respects by the laws of the State of Delaware without regard to conflict of laws
principles.

IN WITNESS WHEREOF, the parties hereto have executed this Amendment No. 2 as of
the day and year first written above.

              CALAMOS ASSET MANAGEMENT, INC.   CALAMOS FAMILY PARTNERS, INC.
 
           
By:
  /s/ James S. Hamman, Jr.   By:   /s/ John P. Calamos, Sr.
 
  James S. Hamman, Jr.
EVP, General Counsel & Secretary       John P. Calamos, Sr.
 
            /s/ John P. Calamos, Sr.         John P. Calamos, Sr.