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                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549


                                   FORM 10-Q/A
                                 Amendment No. 1

[X]      QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
         EXCHANGE ACT OF 1934

         For Quarterly Period Ended September 30, 1998

[ ]      TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
         EXCHANGE ACT OF 1934

         For The Transition Period From          to


                         Commission file number 1-3672.


                     CENTRAL ILLINOIS PUBLIC SERVICE COMPANY
             (Exact name of registrant as specified in its charter)


         Illinois                                                37-0211380
(State or other jurisdiction of                               (I.R.S. Employer
incorporation or organization)                               Identification No.)


               607 East Adams Street, Springfield, Illinois 62739
              (Address of principal executive offices and Zip Code)



                         Registrant's telephone number,
                       including area code: (217) 523-3600



         Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the  Securities  Exchange  Act of
1934  during  the  preceding  12 months  (or for such  shorter  period  that the
registrant was required to file such reports),  and (2) has been subject to such
filing requirements for the past 90 days.



                                Yes  X .   No   .



Shares outstanding of each of registrant's classes of common stock as of October
   31, 1998:  Common Stock,  no par value,  held by Ameren  Corporation  (parent
   company of Registrant) - 25,452,373


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                           PART II. OTHER INFORMATION



ITEM 6.  EXHIBITS AND REPORTS ON FORM 8-K

         (a)   Exhibits.

               Exhibit 3(ii)-By-Laws of Central Illinois Public Service Company,
               as amended as of August 24, 1998 (previously filed).

               Exhibit 12 -  Computation  of Ratio of Earnings to Fixed  Charges
               and  Preferred  Stock  Dividend  Requirements,  12  Months  Ended
               September 30, 1998 (previously filed).

               Exhibit  15  -  Awareness Letter  and  Review Reports  from inde-
               pendent accountants  regarding unaudited interim financial infor-
               mation,  Three  Months  Ended March 31, 1998,  Six  Months  Ended
               June 30, 1998, and Nine Months Ended September 30, 1998.

               Exhibit 27 - Financial Data Schedule (previously filed).

         (b)  Reports  on Form 8-K.  The  Registrant  filed a report on Form 8-K
dated September 24, 1998 reporting on the impact of Ameren Corporation's (parent
company of the  Registrant)  employee  separation  plan and on the effect of the
final  rule  issued  in  September  1998  by  the  United  States  Environmental
Protection Agency pertaining to nitrogen oxide emissions.



                                   SIGNATURES

         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.


                                        CENTRAL ILLINOIS PUBLIC
                                            SERVICE COMPANY
                                              (Registrant)


                                      By  /s/ Warner L. Baxter
                                        ------------------------
                                              Warner L. Baxter
                                                 Controller



Date: December 15, 1998

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