THE CORPORATE LIBRARY

Related Party Transactions and Outside Related Director Information

Ameren Corporation (AEE)

3/15/2006 Proxy Information

During 2005, subsidiaries of Ameren were parties to certain business transactions with institutions related to directors and nominees. These transactions, which were principally related to the supply of regulated public utility energy services and non-regulated energy services, were done in the ordinary course of business, with terms and conditions the same or substantially the same as those prevailing for comparable transactions with non-affiliated persons. The Board of Directors has determined that these business transactions do not cause a material relationship to exist between the Company and a director or nominee as defined by the NYSE listing standards and the Company’s Policy Regarding Nominations of Directors.

Only Douglas R. Oberhelman had a business relationship with the Company in 2005 that is required to be reported. Mr. Oberhelman is an executive officer of Caterpillar Inc. which purchases regulated public utility energy services and non-regulated energy services from certain of the Company’s subsidiaries (primarily CILCO, Ameren Energy Marketing Company, IP and UE) and sells and leases equipment to and provides maintenance and training services for some of the Ameren subsidiaries. During 2005, revenues from energy sales by Ameren subsidiaries to Caterpillar aggregated approximately $46.8 million excluding revenues from the supply of regulated public utility services and revenues based on competitive bid transactions. Payments made during 2005 by Ameren subsidiaries to Caterpillar for the purchase or lease of equipment aggregated approximately $146,000, for the repurchase of energy aggregated approximately $80,000 and for maintenance and training services aggregated approximately $1.3 million. These transactions, many of which are for multiple year terms, were entered into in the ordinary course of business on an arms length basis. The total of all payments made by the Company’s subsidiaries to Caterpillar and payments received by the Company’s subsidiaries from Caterpillar during 2005 (including payments related to the supply of regulated public utility services and payments related to competitive bid transactions) did not exceed 2 percent of Caterpillar’s 2005 consolidated revenues of approximately $36.339 billion. In addition, the total of all payments made by Ameren subsidiaries to Caterpillar during 2005 was less than 2 percent of Ameren’s 2005 consolidated revenues of approximately $6.78 billion. Caterpillar and Ameren transactions also did not exceed these 2 percent thresholds during 2003 and 2004.

In addition to the above business relationships, certain of the Company’s directors and executive officers had reportable family relationships in 2005. Charles W. Mueller is the father of Michael G. Mueller, President of the Company’s wholly-owned indirect subsidiary, Ameren Energy Fuels and Services Company and a Vice President of Ameren Services, for which he received in 2005 aggregate salary, bonus and other compensation of $345,818 and a restricted stock award of 1,640 shares of Ameren Common Stock, valued at $83,984 based on the closing market price of $51.21 per share on February 11, 2005, the date the restricted stock was awarded. See Footnotes 4 and 5 to the “Summary Compensation Table” under “Executive Compensation” below for information regarding restricted stock awards and other compensation, respectively. Another son of Mr. Mueller, Charles R. Mueller, is employed by IP as a supervising engineer, for which he received aggregate salary, bonus and other compensation of $137,825 for 2005. A sister of Gary L. Rainwater, Patricia A. Fuller, is employed by Ameren Services as a health and welfare consultant in its Human Resources Function, for which she received aggregate salary, bonus and other compensation of $104,436 for 2005. Wendy C. Brumitt, a daughter of Thomas R. Voss, Executive Vice President and Chief Operating Officer of the Company and an executive officer of various Company subsidiaries, is employed by UE as an engineer at its Callaway nuclear plant, for which she received aggregate salary, bonus and other compensation of $85,469 for 2005. Gary L. Weisenborn, a brother of Dennis W. Weisenborn, a Vice President of various Company subsidiaries, is employed by UE as a superintendent for which he received aggregate salary, bonus and other compensation of $132,870 for 2005. Diana L. Weisenborn, the wife of Gary L. Weisenborn and sister-in-law of Dennis W. Weisenborn, is employed by Ameren Services as an executive secretary, for which she received aggregate salary, bonus and other compensation of $68,095 for 2005. Jennifer Curtis, a daughter of Craig D. Nelson, a Vice President of various Company subsidiaries, is employed by CILCO as a supervisor for customer accounts, for which she received aggregate salary, bonus and other compensation of $75,866 for 2005. Susan M. Prebil, wife of William J. Prebil, a Vice President of various Company subsidiaries, was employed by CILCO as a settlement specialist during a portion of 2005 for which she received salary and other compensation of $4,056. In 2005, Mrs. Prebil terminated her 28 year employment with CILCO pursuant to a voluntary separation program and in that connection received aggregate compensation of $103,644. David E. Boll, a brother-in-law of Robert F. Neff, a Vice President of Ameren Energy Fuels and Services Company, is employed by Ameren Services as a managing supervisor of mechanical engineering for which he received aggregate salary, bonus and other compensation of $111,401 for 2005. Ricky W. Rogers, a brother-in-law of Timothy E. Herrmann, a Vice President of UE as of January 1, 2006, is employed by UE as substation traveling operator for which he received aggregate salary, bonus and other compensation of $80,715 for 2005.

3/15/2005 Proxy Information

Messrs. William E. Cornelius and Clifford L. Greenwalt, former officers of Ameren or its affiliates, have been retired for over five years and are considered to no longer have a material relationship with Ameren.

During 2004, subsidiaries of Ameren were parties to certain business transactions with institutions related to directors and nominees. These transactions, which were principally related to the supply of regulated public utility energy services and non-regulated energy services, were done in the ordinary course of business, with terms and conditions the same or substantially the same as those prevailing for comparable transactions with non-affiliated persons. The Board of Directors has determined that these business transactions do not cause a material relationship to exist between the Company and a director or nominee as defined by the NYSE listing standards and the Company’s Policy Regarding Nominations of Directors.

Only Messrs. Oberhelman and Cornelius had business relationships with the Company in 2004 that are required to be reported. Mr. Oberhelman is an executive officer of Caterpillar Inc. which purchases regulated public utility energy services and non-regulated energy services from certain of the Company’s subsidiaries (primarily CILCO, Ameren Energy Marketing Company, IP and UE) and sells and leases equipment to some of the Ameren subsidiaries. During 2004, revenues from energy sales by Ameren subsidiaries to Caterpillar aggregated approximately $41 million excluding revenues from the supply of regulated public utility services and revenues based on competitive bid transactions. Payments made during 2004 by Ameren subsidiaries to Caterpillar for the purchase or lease of equipment aggregated approximately $1.8 million and for the repurchase of energy aggregated approximately $84,000. These transactions, many of which are for multiple year terms, were entered into in the ordinary course of business on an arms length basis. The total of all payments made by the Company’s subsidiaries to Caterpillar and payments received by the Company’s subsidiaries from Caterpillar during 2004 (including payments related to the supply of regulated public utility services and payments related to competitive bid transactions) did not exceed 2 percent of Caterpillar’s 2004 consolidated revenues of approximately $30.25 billion. In addition, the total of all payments made by Ameren subsidiaries to Caterpillar during 2004 were less than 2 percent of Ameren’s 2004 consolidated revenues of approximately $5.2 billion.

Mr. Cornelius has served as an advisor to the Company’s Board of Directors since his retirement as a director in April 2004. He received cash compensation of $22,336 for his service as an advisor in 2004. See the table under “Director Compensation” above for his total director and advisor compensation in 2004.

In addition to the above business relationships, certain of the Company’s directors and executive officers had reportable family relationships in 2004. Charles W. Mueller is the father of Michael G. Mueller, President of the Company’s wholly-owned indirect subsidiary, Ameren Energy Fuels and Services Company and Vice President of Ameren Services, for which he received in 2004 aggregate salary, bonus and other compensation of $314,887 and a restricted stock award of 1,726 shares of Ameren Common Stock, valued at $79,983 based on the closing market price of $46.34 per share on February 13, 2004, the date the restricted stock was awarded. See Footnotes 3 and 4 to the “Summary Compensation Table” under “Executive Compensation” below for information regarding restricted stock awards and other compensation, respectively. Another son of Mr. Mueller, Charles R. Mueller, is employed by recently acquired IP as a supervising engineer, for which he received aggregate salary and bonus of $141,088 for 2004. A sister of Gary L. Rainwater, Patricia A. Fuller, is employed by Ameren Services as a supervisor in its Human Resources Function, for which she received aggregate salary and bonus of $99,480 for 2004. Wendy C. Brumitt, a daughter of Thomas R. Voss, Executive Vice President and Chief Operating Officer of the Company and an executive officer of various Company subsidiaries, is employed by UE as an engineer at its Callaway nuclear plant, for which she received aggregate salary and bonus of $71,047 for 2004. Gary L. Weisenborn, a brother of Dennis W. Weisenborn, a Vice President of various Company subsidiaries, is employed by UE as a power plant superintendent for which he received aggregate salary and bonus of $127,178 for 2004. Diana L. Weisenborn, the wife of Gary L. Weisenborn and sister-in-law of Dennis W. Weisenborn, is employed by Ameren Services as an executive secretary, for which she received aggregate salary and bonus of $60,422 for 2004. Jennifer Curtis, a daughter of Craig D. Nelson, a Vice President of various Company subsidiaries, is employed by CILCO as a supervisor in its Credit Department, for which she received aggregate salary and bonus of $62,366 for 2004.

3/17/2004 Proxy Information

Charles W. Mueller was Chairman and Chief Executive Officer of Ameren Corporation.

William E. Cornelius joined Union Electric in 1962, became President in 1980, Chief Executive Officer in 1984 and served as Chairman from 1988 until his retirement in 1994.

During 2003, subsidiaries of Ameren were parties to certain business transactions with institutions related to directors and nominees. These transactions, which were principally related to the supply of regulated public utility energy services and non-regulated energy services, were done in the ordinary course of business, with terms and conditions the same or substantially the same as those prevailing for comparable transactions with non- affiliated persons. The Board of Directors has determined that none of these business transactions cause a material relationship to exist between the Company and a director or nominee as defined by the NYSE listing standards and the Company’s Policy Regarding Nominations of Directors.

Only Mr. Douglas R. Oberhelman had a business relationship with the Company in 2003 that is required to be reported. Mr. Oberhelman is an executive officer of Caterpillar Inc. which purchases regulated public utility energy services and non-regulated energy services from certain of the Company’s subsidiaries (primarily CILCO, Ameren Energy Marketing Company and UE) and sells and leases equipment to some of the Ameren subsidiaries. During 2003, revenues from energy sales by Ameren subsidiaries to Caterpillar aggregated approximately $32 million excluding revenues from the supply of regulated public utility services and revenues based on competitive bid transactions. Payments made by Ameren subsidiaries to Caterpillar for the purchase or lease of equipment during 2003 aggregated approximately $352,000. These transactions, many of which are for multiple year terms, were entered into in the ordinary course of business on an arms length basis. The total of all payments made by the Company’s subsidiaries to Caterpillar and payments received by the Company’s subsidiaries from Caterpillar during 2003 (including payments related to the supply of regulated public utility services and payments related to competitive bid transactions) did not exceed 2% of Caterpillar’s 2003 consolidated revenues of approximately $22.76 billion. In addition, the total of all payments made by Ameren subsidiaries to Caterpillar during 2003 were less than 2% of Ameren’s 2003 consolidated revenues of approximately $4.59 billion.

3/14/2003 Proxy Information

Mr. Douglas R. Oberhelman is an executive officer of Caterpillar Inc. which has commercial relationships with certain of the Company's subsidiaries (primarily the CILCORP companies) that provide regulated public utility energy services and unregulated energy services. During 2002, revenues from transactions with Caterpillar aggregated approximately $25 million excluding revenues from the supply of regulated public utility services and revenues based on competitive bid transactions. These transactions, many of which are for multiple year terms, were entered into at arms length and did not exceed 5% of Ameren's consolidated gross revenues for fiscal year 2002. Applying this percentage of revenues test, the Board of Directors has determined that Mr. Oberhelman does not have a material relationship with the Company. In 2003, an existing contract between an Ameren public utility subsidiary and Caterpillar for the supply of energy services will expire and is expected to be replaced with a multi-year contract with an unregulated Ameren subsidiary that will provide annual revenues of approximately $11 million. This transaction will not cause unregulated revenues from Caterpillar to exceed 5% of Ameren's consolidated gross revenues for fiscal year 2003.

Messrs. William E. Cornelius and Clifford L. Greenwalt, former officers of Ameren or its affiliates, have been retired for over five years and are considered to no longer have a material relationship with Ameren.

Charles W. Mueller is the father of Michael G. Mueller, who is a Vice President of certain Company subsidiaries.