Ameren 10-Q 2004 Q2 Quarterly report

EXHIBIT 31.2

SECTION 302 CERTIFICATION

I, Nick J. Caruso, certify that:

1. I have reviewed this quarterly report on Form 10-Q of Illinois Power Company ("IP");

2. Based on my knowledge, this quarterly report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this quarterly report;

3. Based on my knowledge, the financial statements, and other financial information included in this quarterly report, fairly present in all material respects the financial condition, results of operations and cash flows of IP as of, and for, the periods presented in this quarterly report;

4. IP’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for IP and have:

(a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designedunder our supervision, to ensure that material information relating to IP, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this quarterly report is being prepared;

(b) Evaluated the effectiveness of IP’s disclosure controls and procedures and presented in this quarterly report ourconclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this quarterly report based on such evaluation; and

(c) Disclosed in this quarterly report any change in IP’s internal control over financial reporting that occurred during IP’s most recent fiscal quarter that has materially affected, or is reasonably likely to materially affect, IP’s internal control over financial reporting; and

5. IP’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to IP’s auditors and the audit committee of IP’s board of directors (or persons performing the equivalent functions):

(a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect IP’s ability to record, process, summarize and report financial information; and

(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in IP’s internal control over financial reporting.

Date: August 11, 2004	By:	/s/  Nick J. Caruso
		Nick J. Caruso Executive Vice President and Chief Financial Officer