Exhibit 10.4
AMENDMENT NO. 1
TO THE EXECUTIVE EMPLOYMENT AGREEMENT OF
JAMES S. HAMMAN, JR.
AMENDMENT NO. 1, dated as of June 1, 2007 (“Amendment No. 1”), to the Executive
Employment Agreement of James S. Hamman, Jr. dated as of October 26, 2004 (the
“Agreement”), by and among Calamos Asset Management, Inc., a Delaware
Corporation, Calamos Advisors LLC., a Delaware Limited Liability Company, and
James S. Hamman, Jr., an individual.
WHEREAS, pursuant to Section 14 of the Agreement, the parties hereto desire to
amend the terms of the Agreement to reflect a certain revision.
NOW, THEREFORE, the parties hereto hereby agree as follows:

  1.   Amendment. Section 4(c)(i)(B)(2) of the Agreement is hereby amended to
provide as follows: “any material adverse change in the status, position or
responsibilities of Executive, including a change in Executive’s reporting
relationship;”.     2.   Reaffirmation. In all other respects the Agreement
remains the same and in full force and effect.     3.   Effective Date. This
Amendment No. 1 shall become effective as of the date first written above (the
“Effective Date”). On and after the Effective Date of this Amendment No. 1, each
reference in the Agreement to “this Agreement,” “hereunder,” “hereof,” or words
of like import referring to the Agreement shall mean and be a reference to the
Agreement as amended by this Amendment No. 1.     4.   Governing Law. The
validity and construction of this Amendment No. 1 shall be determined and
governed in all respects by the laws of the State of Illinois without regard to
conflict of laws principles.

IN WITNESS WHEREOF, the parties hereto have executed this Amendment No. 1 as of
the day and year first written above.

                      CALAMOS ASSET MANAGEMENT, INC.       JAMES S. HAMMAN, JR.
   
 
                   
 
  By:
Its:   /s/ John P. Calamos, Sr.
 
Chairman, CEO & Co-CIO
 
       /s/ James S. Hamman, Jr.
 
   
 
                    CALAMOS ADVISORS LLC            
 
                   
 
  By:
Its:   /s/ Patrick H. Dudasik
 
EVP, COO, CFO & Treasurer