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Illinois Power 8-K Dated 05/19/05
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STATES</FONT></DIV>
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align=center><FONT
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AND EXCHANGE COMMISSION</FONT></DIV>
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align=center><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">Washington,
D.C. 20549</FONT></DIV>
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      align=center><FONT
      style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">FORM
      8-K</FONT></DIV></TD></TR>
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<DIV
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align=center><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">CURRENT
REPORT</FONT></DIV>
<DIV
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align=center><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">Pursuant
to Section 13 or 15(d) of the</FONT></DIV>
<DIV
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align=center><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">Securities
Exchange Act of 1934</FONT></DIV>
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align=center><BR></DIV>
<DIV
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align=center><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">Date of
report (Date of earliest event reported):</FONT><FONT id=TAB2
style="COLOR: black; LETTER-SPACING: 27pt">&nbsp;</FONT></DIV>
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      <DIV
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      align=center><FONT
      style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">May
      17, 2005 </FONT></DIV></TD></TR></TABLE></DIV>
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align=left><BR></DIV>
<DIV
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align=center><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">ILLINOIS
POWER COMPANY</FONT></DIV>
<DIV
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align=center><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">(Exact
Name of Registrant as Specified in its Charter)</FONT></DIV>
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      align=center><FONT
      style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">Illinois</FONT></DIV></TD>
    <TD vAlign=top align=middle width="19%">
      <DIV
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      align=center><FONT
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      <DIV
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      align=center><FONT
      style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">37-0344645</FONT></DIV></TD></TR>
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      align=center><FONT
      style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">(State
      or Other Jurisdiction</FONT></DIV></TD>
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      align=center><FONT
      style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">(I.R.S.
      Employer</FONT></DIV></TD></TR>
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      align=center><FONT
      style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">of
      Incorporation)</FONT></DIV>
      <DIV
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      align=justify>&nbsp;</DIV></TD>
    <TD vAlign=top align=middle width="19%">
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      align=center><FONT
      style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">File
      Number)</FONT></DIV>
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      align=justify>&nbsp;</DIV></TD>
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      <DIV
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      align=center><FONT
      style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">Identification
      No.)</FONT></DIV>
      <DIV
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      align=justify>&nbsp;</DIV></TD></TR></TABLE></DIV>
<DIV></DIV><BR></DIV>
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align=left>&nbsp;</DIV>
<DIV
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align=left><BR>&nbsp;</DIV>
<DIV
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align=center><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">500 S.
27th Street, Decatur, Illinois 62521-2200</FONT></DIV>
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align=center><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">(Address
of Principal Executive Offices and Zip Code)</FONT></DIV>
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align=center><BR></DIV>
<DIV
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align=center>&nbsp;</DIV>
<DIV
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align=center><BR></DIV>
<DIV
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align=center><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">Registrant&#8217;s
telephone number, including area code: (217) 424-6600</FONT></DIV>
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align=left><BR></DIV>
<DIV
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align=justify>&nbsp;</DIV>
<DIV
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align=left>&nbsp;</DIV>
<DIV
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align=justify>&nbsp;</DIV>
<DIV
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align=left><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">Check the
appropriate box below if the Form 8-K filing is intended to simultaneously
satisfy the filing obligation of the registrant under any of the following
provisions:</FONT></DIV>
<DIV
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align=justify>&nbsp;</DIV>
<DIV
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align=left><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">[ ]
Written communications pursuant to Rule 425 under the Securities Act (17 CFR
230.425)</FONT></DIV>
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align=justify>&nbsp;</DIV>
<DIV
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align=left><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">[ ]
Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR
240.14a-12)</FONT></DIV>
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align=justify>&nbsp;</DIV>
<DIV
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align=left><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">[ ]
Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act
(17 CFR 240.14d-2(b))</FONT></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=justify>&nbsp;</DIV>
<DIV
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align=left><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">[ ]
Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act
(17 CFR 240.13e-4(c))</FONT></DIV>
<DIV
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align=justify>&nbsp;</DIV>
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align=left><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"></FONT>&nbsp;</DIV>
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style="DISPLAY: inline; FONT-SIZE: 8pt; COLOR: #000000; FONT-FAMILY: Times New Roman"></FONT></DIV></DIV></DIV>
<DIV
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align=left><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"></FONT>&nbsp;</DIV>
<DIV
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align=left><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"></FONT>&nbsp;</DIV>
<DIV
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align=left><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">SECTION 8
- OTHER EVENTS</FONT></DIV>
<DIV
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align=justify>&nbsp;</DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">ITEM 8.01
&nbsp;Other Events.</FONT></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=justify><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"></FONT>&nbsp;</DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=justify><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"><FONT
id=TAB2 style="LETTER-SPACING: 9pt">&nbsp;&nbsp;&nbsp;</FONT>&nbsp;Reference is
made to Note 3 - Rate and Regulatory Matters (Illinois-Gas) to financial
statements under Part&nbsp;I, Item 1, of Illinois Power Company&#8217;s (the
&#8220;Registrant&#8221;) quarterly report on Form 10-Q for the quarterly period ended March
31, 2005 for a discussion of the Registrant&#8217;s request to the Illinois Commerce
Commission (ICC) for an increase in natural gas delivery rates. On May 19, 2005,
Ameren Corporation, the parent company of the Registrant, issued a press release
announcing that the ICC on May 17, 2005 authorized the Registrant to increase
its natural gas delivery rates by approximately $11.3 million annually. A copy
of the press release is included as Exhibit 99.1 and incorporated by reference
herein. </FONT></DIV>
<DIV
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align=justify>&nbsp;</DIV>
<DIV
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align=left>&nbsp;</DIV>
<DIV
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align=left><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">SECTION 9
- </FONT><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">FINANCIAL
STATEMENTS AND EXHIBITS</FONT></DIV>
<DIV
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align=justify>&nbsp;</DIV>
<DIV
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align=left><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">Item
9.01&nbsp; Financial Statements and Exhibits.</FONT></DIV>
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align=justify>&nbsp;</DIV>
<DIV
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align=left><FONT id=TAB1 style="MARGIN-LEFT: 36pt"></FONT><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"><U>Exhibit
Number:</U>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</FONT><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"><U>Title:</U></FONT></DIV>
<DIV
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align=justify>&nbsp;</DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><FONT id=TAB1 style="MARGIN-LEFT: 36pt"></FONT><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">99.1</FONT><FONT
id=TAB2 style="COLOR: black; LETTER-SPACING: 27pt">&nbsp;</FONT><FONT id=TAB2
style="COLOR: black; LETTER-SPACING: 27pt">&nbsp;</FONT><FONT id=TAB2
style="COLOR: black; LETTER-SPACING: 27pt">&nbsp;<FONT id=TAB2
style="LETTER-SPACING: 9pt">&nbsp;&nbsp;&nbsp;</FONT>&nbsp;<FONT id=TAB2
style="LETTER-SPACING: 9pt">&nbsp;&nbsp;&nbsp;</FONT></FONT><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">Press
release regarding ICC authorization granted to the Registrant&nbsp;</FONT></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"><FONT
id=TAB2 style="LETTER-SPACING: 9pt">&nbsp;&nbsp;&nbsp;</FONT>&nbsp;<FONT id=TAB2
style="LETTER-SPACING: 9pt">&nbsp;&nbsp;&nbsp;</FONT>&nbsp;<FONT id=TAB2
style="LETTER-SPACING: 9pt">&nbsp;&nbsp;&nbsp;</FONT>&nbsp;<FONT id=TAB2
style="LETTER-SPACING: 9pt">&nbsp;&nbsp;&nbsp;</FONT>&nbsp;<FONT id=TAB2
style="LETTER-SPACING: 9pt">&nbsp;&nbsp;&nbsp;</FONT>&nbsp;<FONT id=TAB2
style="LETTER-SPACING: 9pt">&nbsp;&nbsp;&nbsp;</FONT>&nbsp;&nbsp;&nbsp;&nbsp; to
increase natural gas delivery rates, issued on May 19, 2005 by Ameren
Corporation.</FONT></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><BR></DIV>
<DIV
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align=justify>&nbsp;</DIV>
<DIV
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align=justify>&nbsp;</DIV>
<DIV
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align=left><BR></DIV>
<DIV
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align=justify>&nbsp;</DIV>
<DIV
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align=center><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">SIGNATURE</FONT></DIV>
<DIV
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align=justify>&nbsp;</DIV>
<DIV
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align=left><BR></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=justify>&nbsp;</DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">Pursuant
to the requirements of the Securities Exchange Act of 1934, the Registrant has
duly caused this report to be signed on its behalf by the undersigned thereunto
duly authorized. </FONT></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><FONT size=2></FONT>&nbsp;</DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left>
<TABLE cellSpacing=0 cellPadding=0 width="100%" align=center bgColor=#ffffff
border=0>
  <TR vAlign=top bgColor=#ffffff>
    <TD width="50%"><FONT face="Times New Roman" size=2>&nbsp;</FONT></TD>
    <TD width="1%"><FONT face="Times New Roman" size=2>&nbsp;</FONT></TD>
    <TD width="49%"><FONT face="Times New Roman" size=2>&nbsp;</FONT></TD></TR>
  <TR vAlign=top bgColor=#ffffff>
    <TD><FONT face="Times New Roman" size=2>&nbsp;</FONT></TD>
    <TD colSpan=2><FONT face="Times New Roman" size=2>ILLINOIS POWER
      COMPANY<BR>(Registrant)</FONT></TD></TR>
  <TR vAlign=top bgColor=#ffffff>
    <TD><FONT face="Times New Roman" size=2>&nbsp;<BR>&nbsp;</FONT></TD>
    <TD><FONT face="Times New Roman" size=2>&nbsp;<BR>&nbsp;</FONT></TD>
    <TD><FONT face="Times New Roman" size=2>&nbsp;<BR>&nbsp;</FONT></TD></TR>
  <TR vAlign=top bgColor=#ffffff>
    <TD><FONT face="Times New Roman" size=2></FONT></TD>
    <TD><FONT face="Times New Roman" size=2>By:&nbsp;&nbsp;</FONT></TD>
    <TD><FONT face="Times New Roman" size=2>/s/&nbsp;Martin J.
  Lyons</FONT></TD></TR>
  <TR vAlign=top bgColor=#ffffff>
    <TD colSpan=2><FONT face="Times New Roman" size=1>&nbsp;</FONT></TD>
    <TD align=left>
      <HR align=left width="80%" color=#000000 noShade SIZE=2>
      <FONT
      style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">Martin
      J. Lyons</FONT></TD></TR>
  <TR vAlign=top bgColor=#ffffff>
    <TD colSpan=2><FONT face="Times New Roman" size=2>&nbsp;</FONT></TD>
    <TD><FONT face="Times New Roman" size=2>Vice President and
      Controller<BR>(Principal Accounting Officer)</FONT></TD></TR></TABLE></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=justify>&nbsp;</DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><BR></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=justify>&nbsp;</DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 207pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><BR></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">Date: May
19, 2005 </FONT></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=justify>&nbsp;</DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><BR></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=justify>&nbsp;</DIV>
<DIV></DIV><BR>
<DIV id=PGBRK style="MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt">
<DIV id=FTR>
<DIV style="WIDTH: 100%" align=left>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=justify>&nbsp;</DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><BR></DIV></DIV>
<DIV id=GLFTR
style="MARGIN-LEFT: 0pt; WIDTH: 100%; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt"
align=center><FONT
style="DISPLAY: inline; FONT-SIZE: 8pt; COLOR: #000000; FONT-FAMILY: Times New Roman">-2-</FONT></DIV></DIV>
<DIV id=PN style="PAGE-BREAK-AFTER: always">
<DIV style="WIDTH: 100%; TEXT-ALIGN: center"><FONT
style="DISPLAY: inline; FONT-SIZE: 8pt" face="Times New Roman"></FONT></DIV>
<DIV style="WIDTH: 100%; TEXT-ALIGN: center">
<HR color=#000000 noShade SIZE=2>
</DIV></DIV>
<DIV id=HDR>
<DIV id=GLHDR style="WIDTH: 100%" align=right><FONT
style="DISPLAY: inline; FONT-SIZE: 8pt; COLOR: #000000; FONT-FAMILY: Times New Roman"></FONT></DIV>
<DIV style="WIDTH: 100%" align=left></DIV></DIV></DIV><BR><BR>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=center><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"><U>Exhibit
Index</U></FONT></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=center><BR></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"><U>Exhibit
No.</U></FONT><FONT id=TAB2
style="COLOR: black; LETTER-SPACING: 99pt">&nbsp;</FONT><FONT id=TAB2
style="COLOR: black; LETTER-SPACING: 63pt">&nbsp;<FONT id=TAB2
style="LETTER-SPACING: 9pt">&nbsp;&nbsp;&nbsp;</FONT>&nbsp;<FONT id=TAB2
style="LETTER-SPACING: 9pt">&nbsp;&nbsp;&nbsp;</FONT>&nbsp;<FONT id=TAB2
style="LETTER-SPACING: 9pt">&nbsp;&nbsp;&nbsp;</FONT>&nbsp;<FONT id=TAB2
style="LETTER-SPACING: 9pt">&nbsp;&nbsp;&nbsp;</FONT>&nbsp;<FONT id=TAB2
style="LETTER-SPACING: 9pt">&nbsp;&nbsp;&nbsp;</FONT>&nbsp;</FONT><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman"><U>Description</U></FONT></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><BR></DIV>
<DIV>
<TABLE id=hangingindent cellSpacing=0 cellPadding=0 width="100%" align=center
border=0>
  <TR style="LINE-HEIGHT: 1.25" vAlign=top>
    <TD style="WIDTH: 18pt">
      <DIV
    style="MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt"></DIV></TD>
    <TD style="WIDTH: 90pt">
      <DIV style="MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt"><FONT
      style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">99.1</FONT></DIV></TD>
    <TD style="WIDTH: 9pt">
      <DIV style="MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt"><FONT
      style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">-</FONT></DIV></TD>
    <TD>
      <DIV style="MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt"><FONT
      style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">Press
      release regarding Illinois Commerce Commission authorization granted
      </FONT></DIV></TD></TR></TABLE></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 117pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">to
Illinois Power Company to increase natural gas delivery rates, issued on
</FONT></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 117pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><FONT
style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">May 19,
2005 by Ameren Corporation.</FONT></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 81pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><BR></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><BR></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><BR></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><BR></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=left><BR></DIV>
<DIV
style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.25; MARGIN-RIGHT: 0pt"
align=justify>&nbsp;</DIV>
<DIV></DIV></BODY></HTML>
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Illinois Power 8-K Dated 05/19/05
UNITED
STATES
SECURITIES
AND EXCHANGE COMMISSION
Washington,
D.C. 20549
FORM
      8-K
CURRENT
REPORT
Pursuant
to Section 13 or 15(d) of the
Securities
Exchange Act of 1934
Date of
report (Date of earliest event reported):
May
      17, 2005
ILLINOIS
POWER COMPANY
(Exact
Name of Registrant as Specified in its Charter)
Illinois
1-3004
37-0344645
(State
      or Other Jurisdiction
(Commission
(I.R.S.
      Employer
of
      Incorporation)
File
      Number)
Identification
      No.)
500 S.
27th Street, Decatur, Illinois 62521-2200
(Address
of Principal Executive Offices and Zip Code)
Registrant's
telephone number, including area code: (217) 424-6600
Check the
appropriate box below if the Form 8-K filing is intended to simultaneously
satisfy the filing obligation of the registrant under any of the following
provisions:
[ ]
Written communications pursuant to Rule 425 under the Securities Act (17 CFR
230.425)
[ ]
Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR
240.14a-12)
[ ]
Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act
(17 CFR 240.14d-2(b))
[ ]
Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act
(17 CFR 240.13e-4(c))
SECTION 8
- OTHER EVENTS
ITEM 8.01
 Other Events.
Reference is
made to Note 3 - Rate and Regulatory Matters (Illinois-Gas) to financial
statements under Part I, Item 1, of Illinois Power Company's (the
"Registrant") quarterly report on Form 10-Q for the quarterly period ended March
31, 2005 for a discussion of the Registrant's request to the Illinois Commerce
Commission (ICC) for an increase in natural gas delivery rates. On May 19, 2005,
Ameren Corporation, the parent company of the Registrant, issued a press release
announcing that the ICC on May 17, 2005 authorized the Registrant to increase
its natural gas delivery rates by approximately $11.3 million annually. A copy
of the press release is included as Exhibit 99.1 and incorporated by reference
herein.
SECTION 9
-
FINANCIAL
STATEMENTS AND EXHIBITS
Item
9.01  Financial Statements and Exhibits.
Exhibit
Number:
Title:
99.1
Press
release regarding ICC authorization granted to the Registrant
to
increase natural gas delivery rates, issued on May 19, 2005 by Ameren
Corporation.
SIGNATURE
Pursuant
to the requirements of the Securities Exchange Act of 1934, the Registrant has
duly caused this report to be signed on its behalf by the undersigned thereunto
duly authorized.
ILLINOIS POWER
      COMPANY
(Registrant)
By:
/s/ Martin J.
  Lyons
Martin
      J. Lyons
Vice President and
      Controller
(Principal Accounting Officer)
Date: May
19, 2005
-2-
Exhibit
Index
Exhibit
No.
Description
99.1
-
Press
      release regarding Illinois Commerce Commission authorization granted
to
Illinois Power Company to increase natural gas delivery rates, issued on
May 19,
2005 by Ameren Corporation.