FIRST AMENDMENT TO THE AMEREN SUPPLEMENTAL RETIREMENT PLAN

Exhibit 10.44

FIRST AMENDMENT TO THE

AMEREN SUPPLEMENTAL RETIREMENT PLAN

WHEREAS, Ameren Corporation (“Ameren”) previously adopted the Ameren Supplemental Retirement Plan (“Plan”); and

WHEREAS, Ameren previously acquired Central Illinois Light Company (“CILCO”) and became the sponsor of the CILCO Benefit Replacement Plan (“BRP”); and

WHEREAS, Ameren reserved the right to amend the Plan and the BRP; and

WHEREAS, Ameren desires to merge the BRP into the Plan effective November 1, 2008;

NOW THEREFORE, effective November 1, 2008, the BRP is merged into the Plan, and the Plan is amended by adding a new Schedule B as attached hereto; and

RESOLVED FURTHER, the terms of the BRP in effect prior to the merger shall continue to apply with respect to a participant who terminated employment prior to January 1, 2005, and the benefits of such participants shall be “grandfathered” for purposes of Section 409A of the Internal Revenue Code of 1986, as amended.

IN WITNESS WHEREOF, this Amendment is executed as of the date below.