<PAGE>

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 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):
                                November 24, 1999





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




         Illinois                          1-3672                37-0211380
(State or other jurisdiction          (Commission             (I.R.S. Employer
    of incorporation)                File Number)            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


<PAGE>


ITEM 5.  OTHER EVENTS

     Reference  is made to  Management's  Discussion  and  Analysis of Financial
Condition and Results of  Operations  under the caption  "Liquidity  and Capital
Resources" in the  Registrant's  Form 10-Q for the quarter  ended  September 30,
1999,  for a discussion of cost  reduction  alternatives  being  explored by the
Registrant.  In late November and  mid-December  1999, the Registrant and two of
its coal suppliers  executed  agreements to terminate their existing coal supply
contracts effective December 31, 1999. Under the agreements, the Registrant will
make termination  payments to the suppliers totaling  approximately $52 million.
These  termination  payments  will be recorded as a  nonrecurring  charge in the
fourth quarter of 1999, equivalent to $31 million, after income taxes.

     Total  pre-tax  fuel cost  savings from these  termination  agreements  are
estimated to be $183 million (or $131 million net of the  termination  payments)
through 2010 which is the maximum  period that would have remained on any of the
terminated coal supply contracts. Approximately $66 million of pre-tax fuel cost
savings is expected to be realized over the next three years.

     The  foregoing  estimates of the savings from the  termination  of the coal
supply contracts are forward-looking  statements within the meaning of the "Safe
Harbor" provisions of the Private Securities Litigation Reform Act of 1995. Such
statements  involve risks and  uncertainties  that could cause actual results to
differ  materially  from those  discussed  herein.  Among the factors that could
affect actual results is the future market price for fuel.




                                    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.

                                                 CENTRAL ILLINOIS PUBLIC
                                                    SERVICE COMPANY
                                                      (Registrant)


                                                 By   /s/ Warner L. Baxter
                                                    ------------------------
                                                        Warner L. Baxter
                                                  Vice President and Controller
                                                  (Principal Accounting Officer)

Date:  December 20, 1999
[{"type": "8-K", "sequence": "1", "description": "FORM 8-K FOR CENTRAL ILL. PUBLIC SERVICE COMPANY", "secsgml_size_bytes": 3614}]
{"company-data": {"conformed-name": "CENTRAL ILLINOIS PUBLIC SERVICE CO", "cik": "0000018654", "assigned-sic": "4931", "irs-number": "370211380", "state-of-incorporation": "IL", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "001-03672", "film-number": "99777243"}, "business-address": {"street1": "607 E ADAMS ST", "city": "SPRINGFIELD", "state": "IL", "zip": "62739", "phone": "2175233600"}, "mail-address": {"street1": "CENTRAL ILLINOIS PUBLIC SERVICE CO", "street2": "607 E ADAMS ST", "city": "SPRINGFIELD", "state": "IL", "zip": "62739"}}
UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 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):
                                November 24, 1999

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

         Illinois                          1-3672                37-0211380
(State or other jurisdiction          (Commission             (I.R.S. Employer
    of incorporation)                File Number)            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
ITEM 5.  OTHER EVENTS

     Reference  is made to  Management's  Discussion  and  Analysis of Financial
Condition and Results of  Operations  under the caption  "Liquidity  and Capital
Resources" in the  Registrant's  Form 10-Q for the quarter  ended  September 30,
1999,  for a discussion of cost  reduction  alternatives  being  explored by the
Registrant.  In late November and  mid-December  1999, the Registrant and two of
its coal suppliers  executed  agreements to terminate their existing coal supply
contracts effective December 31, 1999. Under the agreements, the Registrant will
make termination  payments to the suppliers totaling  approximately $52 million.
These  termination  payments  will be recorded as a  nonrecurring  charge in the
fourth quarter of 1999, equivalent to $31 million, after income taxes.

     Total  pre-tax  fuel cost  savings from these  termination  agreements  are
estimated to be $183 million (or $131 million net of the  termination  payments)
through 2010 which is the maximum  period that would have remained on any of the
terminated coal supply contracts. Approximately $66 million of pre-tax fuel cost
savings is expected to be realized over the next three years.

     The  foregoing  estimates of the savings from the  termination  of the coal
supply contracts are forward-looking  statements within the meaning of the "Safe
Harbor" provisions of the Private Securities Litigation Reform Act of 1995. Such
statements  involve risks and  uncertainties  that could cause actual results to
differ  materially  from those  discussed  herein.  Among the factors that could
affect actual results is the future market price for fuel.

                                    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.

                                                 CENTRAL ILLINOIS PUBLIC
                                                    SERVICE COMPANY
                                                      (Registrant)

                                                 By   /s/ Warner L. Baxter
                                                    ------------------------
                                                        Warner L. Baxter
                                                  Vice President and Controller
                                                  (Principal Accounting Officer)

Date:  December 20, 1999