<PAGE>

                                                                  Exhibit 10.107

                                                                  EXECUTION COPY

         REIMBURSEMENT AGREEMENT I (this "AGREEMENT") dated as of December 15,
1999 entered into between Bayerische Landesbank International S.A., a banking
institution organized under the laws of Luxembourg (the "BANK") and Midwest
Generation, LLC ("MIDWEST").

         WHEREAS, the Collins Trust I (the "OWNER LESSOR") and Collins Holdings
EME, LLC ("COLLINS HOLDINGS") are party to the Facility Lease Agreement (as the
same may be amended, supplemented or otherwise modified from time to time, the
"FACILITY LEASE") dated as of December 15, 1999;

         WHEREAS, Collins Holdings and Midwest are party to the Facility
Sublease Agreement (as the same may be amended, supplemented or otherwise
modified from time to time, the "FACILITY SUBLEASE") dated as of December 15,
1999;

         WHEREAS, the Owner Lessor wishes to obtain additional credit
enhancement from Midwest in order to support the obligations of Midwest to
Collins Holdings under the Facility Sublease and, concomitantly, the obligations
of Collins Holdings to the Owner Lessor under the Facility Lease;

         In consideration of the issuance by the Bank on the Closing Date of an
irrevocable standby letter of credit in the form attached hereto as Exhibit A
(including any substitutions or replacements thereof in accordance with this
Agreement, as the same may be amended, supplemented or otherwise modified from
time to time, the "LETTER OF CREDIT"), in the amount of U.S.$3,870,000.00 and in
favor of the Beneficiary referred to therein (the "BENEFICIARY"), Midwest and
the Bank hereby agree as follows:

1.       DEFINITIONS. Capitalized terms used in this Agreement, including the
         foregoing Recitals, and not otherwise defined herein shall have the
         respective meanings specified in Annex A hereto.

2.       PAYMENTS: Midwest agrees to reimburse the Bank on demand, in
         immediately available funds by transferring such amounts to First Union
         National Bank (Swift ID: PNBPU S3NNYC), Account No.: 200019 3574483 in
         favor of Bayerische Landesbank International S.A. Luxembourg (SWIFT ID
         BYLAULL), for each payment made by the Bank pursuant to a drawing in
         accordance with the terms and conditions of the Letter of Credit
         together with interest on such amount in accordance with Section 5
         hereof (the "REIMBURSEMENT OBLIGATIONS") until payment in full
         hereunder. Each payment by Midwest to the Bank shall be made in lawful
         currency of the United States, shall be directed to the attention of
         Patricia Sanchez, and shall be identified by the number assigned to the
         Letter of Credit by the Bank.

3.       CANCELLATION: The Letter of Credit may be canceled in accordance with
         the terms and conditions of the Letter of Credit.

<PAGE>

4.       FEES: Midwest will pay the Bank a per annum fee equal to 0.30% of the
         daily average of the amount available for drawing under each Letter of
         Credit, calculated on the basis of a 365 or 366 day year, in each case
         for the actual number of days occurring in the period for which such
         fee is payable, payable in United States currency at the location
         designated herein, quarterly in arrears on the sixth day of each
         January, April, July and October (but if such day is not a Business
         Day, on the next succeeding Business Day), (each, a "QUARTERLY PAYMENT
         DATE") and on the expiration or termination date of such Letter of
         Credit. For each amendment to any Letter of Credit, Midwest will
         immediately pay the Bank a charge of $200 in connection therewith.
         Midwest agrees to pay all fees and charges which are due pursuant to
         the terms of this Agreement by transferring such amounts to First Union
         Bank International, New York, FED ABA No. 026.00509.2, Account No. 2000
         19353009 0 in favor of Bayerische Landesbank International S.A.
         Luxembourg.

5.       INTEREST ON PAYMENTS: The Reimbursement Obligations shall accrue
         interest at the Alternate Base Rate plus the Applicable Margin PLUS 2%
         per annum until the Reimbursement Obligations have been paid in full;
         PROVIDED that, upon the occurrence and during the continuance of any
         Maturity Event, Midwest shall pay, but only to the extent permitted by
         law, interest (after as well as before judgment) on the Reimbursement
         Obligations at a rate per annum equal to the Alternate Base Rate plus
         the Applicable Margin plus 5% per annum until such Maturity Event is
         cured; PROVIDED FURTHER that, in addition to the interest then payable
         on amounts paid under the Letter of Credit pursuant to this Section 5,
         if after each three month period following the occurrence of the
         Maturity Event such Maturity Event shall not have been cured, Midwest
         shall pay, but only to the extent permitted by law, interest on the
         Reimbursement Obligations at an additional 1% per annum until such
         Maturity Event is cured. Interest will be calculated based on the
         actual days outstanding and a 365 or, if appropriate, 366 day year.
         Actual days outstanding means the period from and including the day of
         payment by the Bank to and excluding the day of the Bank's receipt of
         funds from Midwest. Interest under this Section 5 shall be paid on
         demand (or, if no demand is made, on each Quarterly Payment Date) and
         on the date that the Reimbursement Obligations are paid in full.

6.       INDEMNITY: Midwest will absolutely, irrevocably and, except as
         otherwise provided herein, unconditionally indemnify and hold the Bank
         harmless against all loss, cost or expense suffered or incurred by the
         Bank howsoever arising from or in connection with the Letter of Credit,
         EXCEPT for any loss, cost or expense suffered or incurred as a result
         of the gross negligence or willful misconduct of the Bank. Neither the
         Bank nor any of the Bank's correspondents or agents shall be
         responsible for any of the following contingencies, including, but not
         limited to: (a) any acts or omissions of the Beneficiary; (b) the form,
         validity, sufficiency, accuracy, genuineness or legal effect of
         documents specified in the Letter of Credit, even if it should in fact
         be proven to be in any or all respects invalid, insufficient,
         inaccurate, fraudulent or forged, provided that all the documents
         appear on their face to be in accordance with the terms and conditions
         of the Letter of Credit; (c) errors, omissions, interruptions or delays
         in transmission or delivery of any messages, by mail, cable, telegraph,
         telex or otherwise, whether or not they may be indecipherable or errors
         in translation or errors in interpretation of technical terms; (d) any
         loss or delay in the transmission or otherwise of any such document or
         draft; (e)


                                       2
<PAGE>


         consequences of compliance with applicable laws, orders, regulations,
         or directives in effect in places of negotiation or payment of the
         Letter of Credit; or (f) without limiting the foregoing, any
         consequences arising from causes beyond the Bank's control or any act
         or omission by the Bank or any of its correspondents, except to the
         extent that the occurrence of any of the contingencies specified in
         subparagraphs (a) through (f) above is attributable to the gross
         negligence or willful misconduct of the Bank or any of its
         correspondents. The occurrence of any one or more of the above
         contingencies shall not affect or impair the Bank's rights and powers
         hereunder or the obligations of Midwest to the Bank of payment,
         indemnity or reimbursement hereunder. If payment is not made within 5
         Business Days of the date demanded, interest will be charged based on
         the calculation in Section 5.

         This Section 6 shall survive any payment of the Bank's obligations and
         liabilities hereunder and any termination of this Agreement.

7.       CHANGE IN CIRCUMSTANCES: If the Bank determines that any change in any
         law, regulation, guideline or order or in the interpretation thereof by
         any court or administrative or governmental authority charged with the
         administration thereof shall either (i) impose, modify or deem
         applicable any reserve, special deposit or similar requirement against
         the Letter of Credit or require the inclusion of the Letter of Credit
         in calculations related to the Bank's capitalization or (ii) impose any
         other condition regarding this Agreement or the Letter of Credit,
         including, without limitation, any requirement that the Bank pay
         assessments for deposit insurance with respect to the Letter of Credit,
         and the result of any event referred to in clause (i) or (ii) above
         shall be to increase the cost to the Bank of issuing or maintaining the
         Letter of Credit or the reimbursement obligations of Midwest or to
         reduce the amounts receivable by the Bank upon such reimbursement,
         then, upon demand by the Bank, Midwest shall promptly pay to the Bank
         from time to time as specified by the Bank additional amounts which
         shall be sufficient to compensate the Bank for such increased cost or
         reduced receivables. A certificate as to such amounts submitted by the
         Bank to Midwest, stating in reasonable detail the basis of computation,
         shall be presumptive evidence of additional amounts payable under this
         Section 7. Midwest acknowledges that there may be various methods of
         allocating to the Letter of Credit reserve, assessment, capitalization
         or similar costs referred to above and agrees that the allocation of
         the Bank, for purposes of determining such costs, shall be conclusive
         and binding upon Midwest, provided that such allocations are made in
         good faith by a reasonable method and are absent manifest error. If
         payment is not made within 5 Business Days of the date demanded,
         interest will be charged based on the calculation in Section 5.

8.       LIABILITY OF THE BANK: The Bank shall not be responsible for verifying
         the existence of any act, condition or statement made by the
         Beneficiary in relation to any drawing or presentment under the Letter
         of Credit, for the validity or genuineness of certificates or other
         documents delivered under or in connection with the Letter of Credit,
         even if such certificates or other documents should in fact prove to be
         invalid, fraudulent or forged, for any breach of contract between the
         Beneficiary and Midwest, or for any other consequences beyond the
         Bank's control, so long as the Bank acts in good faith and in
         accordance with applicable law and customary banking procedures. The
         Bank may


                                       3
<PAGE>

         accept certificates or other documents that appear on their face to be
         in order without responsibility for further investigation, regardless
         of any notice or information to the contrary, unless otherwise ordered
         by a court of competent jurisdiction. In furtherance of and not in
         limitation of the foregoing, Midwest agrees that any action, inaction
         or omission taken or suffered by the Bank in good faith and in
         accordance with applicable law and customary banking procedures in
         connection with any Letter of Credit or related drafts shall be binding
         on Midwest and shall not result in any liability of the Bank to
         Midwest.

9.       OBLIGATION ABSOLUTE: Midwest's obligation to make each payment under
         this Agreement shall be absolute and unconditional and shall not be
         subject to any defense or be affected by any right of setoff,
         counterclaim or recoupment which Midwest may now or hereafter have
         against the Beneficiary, the Bank or any other person for any reason
         whatsoever.

10.      CONDITIONS PRECEDENT: This Agreement shall become effective upon the
         satisfaction of each of the conditions precedent set forth below:

         (a)      Midwest agrees to deliver to the Bank, a certificate of its
                  Secretary or an Assistant Secretary as to resolutions of its
                  Board of Directors authorizing Midwest to enter into and
                  perform this Agreement and the names and signatures of the
                  officers or other officials of Midwest who are authorized to
                  sign this Agreement, together with certified copies of
                  Midwest's organizational documents and an opinion of counsel
                  to Midwest in form and substance satisfactory to the Bank.

         (b)      The Participation Agreement shall have been duly authorized,
                  executed and delivered by the parties thereto.

         (c)      Each of the conditions precedent contained in Section 4 of the
                  Participation Agreement shall have been satisfied in the
                  opinion of the Bank or waived by the Bank.

         (d)      The Bank shall have received any other certificates, documents
                  or information regarding Midwest as the Bank may reasonably
                  request.

11.      RIGHT OF SETOFF: At any time when any Reimbursement Obligation has not
         been paid (after demand for payment has been made), the Bank is hereby
         authorized at any time and from time to time, without notice to Midwest
         (any such notice being expressly waived by Midwest) to set off and
         apply any and all deposits (general or special, time or demand,
         provisional or final) at any time held and other indebtedness at any
         time owing by the Bank to or for the credit or the account of Midwest
         against any and all of the obligations of Midwest now or thereafter
         existing under this Agreement, irrespective of whether or not the Bank
         shall have made any demand under this Agreement and although such
         obligations may be contingent and unmatured. The Bank agrees promptly
         to notify Midwest after any such setoff and application, provided that
         the failure to give such notice shall not affect the validity of such
         setoff and application. The rights of the Bank under this Section 11
         are in addition to other rights and remedies which the Bank may have
         including, without limitation, other rights of setoff.


                                       4
<PAGE>

12.      NOTICES: Notices and demands under this Agreement shall be in writing
         and will be sufficient if delivered by hand, by United States
         registered or certified mail or personal delivery by overnight mail or
         courier service or by facsimile receipt of which is confirmed by
         telephone. Notices and demands shall be effective when received and
         shall be addressed if to Midwest to:

                                    One Financial Place
                                    440 South LaSalle Street, Suite 3500
                                    Chicago, IL  60605
                                    Attn:  Georgia R. Nelson
                                    Fax No.: (312) 583-6111

         if to the Bank to:         Bayerische Landesbank International S.A.
                                    Corporate Finance Department
                                    3, Rue Jean Monnet
                                    L-2180 Luxembourg
                                    Attn.:   Nadja Bamberg/Serge Dollendorf
                                    Fax No.:  (00352) 42434-3399

13.      NO WAIVERS, REMEDIES: This Agreement may not be amended, waived or
         modified except in writing duly signed by the Bank and Midwest. The
         Bank may elect in its sole discretion not to renew the Letter of Credit
         for additional periods. This Agreement and the terms, covenants and
         conditions hereof shall be binding upon and inure to the benefit of the
         Bank and Midwest and their respective successors. No failure on the
         Bank's part to exercise, and no delay on the Bank's part in exercising,
         any rights, powers or remedies hereunder shall operate as a waiver
         thereof, nor shall any single or partial exercise of any such rights,
         powers or remedies by the Bank preclude any other or further exercising
         thereof or the exercise of any other right, power or remedy. All
         remedies hereunder are cumulative and not exclusive of any other
         remedies provided by law.

14.      SEVERABILITY: Any provision of this Agreement which is prohibited,
         unenforceable or not authorized in any jurisdiction shall, as to such
         jurisdiction, be ineffective to the extent required by law without
         invalidating the remaining provisions hereof or affecting the validity,
         enforceability or legality of such provision in any other jurisdiction.

15.      JURISDICTION/WAIVER OF JURY TRIAL:

         (a)      Any legal action or proceeding against Midwest or the Bank
                  with respect to this Agreement, the Letter of Credit or any of
                  the agreements, documents or instruments delivered in
                  connection herewith or therewith may be brought in the courts
                  of the State of New York or of the United States of America
                  for the Southern District of New York as the party commencing
                  such action or proceeding may elect. By execution and delivery
                  hereof, each party accepts and consents to, for itself and in
                  respect of its property, generally and unconditionally, the
                  jurisdiction of the aforesaid courts. Nothing herein shall
                  limit the right of Midwest or the Bank to bring proceedings
                  against the other party in the courts of any other
                  jurisdiction.

                                       5
<PAGE>

         (b)      Midwest and the Bank knowingly, voluntarily and intentionally
                  waive any and all rights Midwest or the Bank, as the case may
                  be, may have to a trial by jury in respect of any litigation
                  based on, or arising out of, under or in connection with, this
                  Agreement, the Letter of Credit or any other documents and
                  instruments executed in connection herewith.

16.      CONSTRUCTION AND INTERPRETATION: This Agreement shall be governed by
         and construed in accordance with the laws of the State of New York.
         Each Letter of Credit shall be subject to the Uniform Customs and
         Practice for Documentary Credits (1993 Revision), International Chamber
         of Commerce, Paris, France, Publication No. 500 (and any successor
         publication).

17.      COUNTERPARTS. This Agreement may be executed in any number of
         counterparts, each executed counterpart constituting an original but
         all together only one agreement.








                                       6
<PAGE>




         IN WITNESS WHEREOF, the parties have caused this Agreement to be
executed and delivered on the date set forth above by the undersigned thereunto
authorized.

                                            BAYERISCHE LANDESBANK
                                            INTERNATIONAL S.A.


                                            By:   /s/ H. PETER RADERMACHER
                                                --------------------------------
                                                 Name: H. Peter Radermacher
                                                 Title: Directeur - Adjoint


                                            By:  /s/ PETER LANG
                                                --------------------------------
                                                 Name: Peter Lang
                                                 Title: Mandataire Commercial


                                            MIDWEST GENERATION, LLC,


                                            By:  /s/ JOHN P. FINNERAN, JR.
                                                --------------------------------
                                                 Name: John P. Finneran, Jr.
                                                 Title: Vice President


<PAGE>



                                                                         ANNEX A
                                                      TO REIMBURSEMENT AGREEMENT

                                    ARTICLE 1

                                   DEFINITIONS

         Section 1.1 DEFINED TERMS. The following terms (whether or not
underscored) when used in this Agreement, including its preamble and recitals,
shall, except where the context otherwise requires, have the following meanings
(such meanings to be equally applicable to the singular and plural forms
thereof):

         "AGREEMENT" means, on any date, this Agreement together with all
Annexes, Appendices and Exhibits as originally in effect on the Effective Date
and as thereafter from time to time amended, supplemented, amended and restated,
or otherwise modified and in effect on such date.

         "ALTERNATE BASE RATE" means, on any date, a fluctuating rate of
interest per annum equal to the higher of:

                  (a) the rate of interest in effect for such day as publicly
         announced from time to time by the Citibank, N.A. at its principal
         office in New York, New York, as its "base rate." The "base rate" is a
         rate set by the Citibank, N.A. based upon various factors including the
         Bank's cost and desired return, general economic conditions and other
         factors, and is used as a reference point for pricing some loans, which
         may be priced at, above, or below such announced rate; or

                  (b) the Federal Funds Rate most recently determined by the
         Bank plus 1/2 of 1%.

         The Alternate Base Rate is not necessarily intended to be the lowest
rate of interest determined by the Bank in connection with extensions of credit.
Changes in the rate of interest on amounts payable under the Agreement will take
effect simultaneously with each change in the Alternate Base Rate. The Bank will
give notice promptly to Midwest of changes in the Alternate Base Rate.

         "APA" means the Asset Purchase Agreement dated as of December 15, 1999
(as the same may be amended, supplemented or otherwise modified from time to
time) among Funding LLC, the Securitization Company, Citibank, N.A., as agent,
each of the financial institutions party thereto as "Purchasers" and Citicorp
North America, Inc., as operating agent for the Securitization Company and as
agent for the Purchasers and the Securitization Company with respect to the
residual credit enhancement.

         "APPLICABLE MARGIN" means, for any day, the rate per annum in effect
for such day based on the Debt Rating which applies for such day determined as
provided in the Pricing Grid.

         "BANK" has the meaning set forth in the Recitals.


<PAGE>

         "BUSINESS DAY" means any day which is neither a Saturday or Sunday nor
a legal holiday on which banks are authorized or required to be closed in New
York, New York or Luxembourg.

         "CLOSING DATE" means the Closing Date, as defined in the Participation
Agreement.

         "COLLINS HOLDINGS" has the meaning set forth in the Recitals.

         "DEBT RATING" means a rating by each of Moody's and S&P of each of (a)
the Funding LLC Loans, (b) the Holdings Tranche A Loans and (c) the Holdings
Tranche B Loans. If Moody's or S&P shall have changed its system of
classifications after the date hereof, a Debt Rating shall be considered to be
at or above a specified level if it is at or above the new rating which most
closely corresponds to the specified level under the old rating system.

         "EFFECTIVE DATE" means the date this Agreement becomes effective
pursuant to SECTION 10.

         "EME" means Edison Mission Energy, a California corporation.

         "FACILITY LEASE " has the meaning set forth in the Recitals.

         "FACILITY SUBLEASE " has the meaning set forth in the Recitals.

         "FEDERAL FUNDS RATE" means, for any period, a fluctuating interest rate
per annum equal for each day during such period to:

                  (a) the weighted average of the rates on overnight federal
         funds transactions with members of the Federal Reserve System arranged
         by federal funds brokers, as published for such day (or, if such day is
         not a Business Day, for the next preceding Business Day) by the Federal
         Reserve Bank of New York; or

                  (b) if such rate is not so published for any day which is a
         Business Day, the average of the quotations for such day on such
         transactions received by the Bank from up to three federal funds
         brokers of recognized standing selected by the Bank.

         "FUNDING LLC" means Midwest Funding LLC.

         "FUNDING LLC LOANS" means the Advances under and as defined in Asset
Purchase Agreement dated as of December 15, 1999 among Funding LLC, the
Securitization Company, Citibank, N.A., as agent, each of the financial
institutions party thereto as "Purchasers" and Citicorp North America, Inc., as
operating agent for the Securitization Company and as agent for the Purchasers
and the Securitization Company.

         "HEREIN", "HEREOF", "HERETO", "HEREUNDER" and similar terms contained
in this Agreement, any Annex, any Appendix, any Schedule or any Exhibit refer to
this Agreement as a whole and not to any particular Section, paragraph or
provision of this Agreement.


                                       2
<PAGE>

         "HOLDINGS" means Edison Mission Midwest Holdings Co., a subsidiary of
EME and a corporation organized under the laws of the State of Delaware.

         "HOLDINGS CREDIT AGREEMENT" means the Credit Agreement dated as of
December 15, 1999 among Holdings, The Chase Manhattan Bank, as administrative
agent thereunder and the financial institutions who are or may become parties
thereto as "Lenders", as from time to time amended, supplemented, amended and
restated or otherwise, modified and in effect from time to time.

         "HOLDINGS TRANCHE A LOANS" has the meaning assigned to the term
"Tranche A Loans" in the Holdings Credit Agreement.

         "HOLDINGS TRANCHE B LOANS" has the meaning assigned to the term
"Tranche B Loans" in the Holdings Credit Agreement.

         "INCLUDING" means including without limiting the generality of any
description preceding such term, and, for purposes of this Agreement, the
parties hereto agree that the rule of EJUSDEM GENERIS shall not be applicable to
limit a general statement, which is followed by or referable to an enumeration
of specific matters, to matters similar to the matters specifically mentioned.

         "MATURITY EVENT" means, at any time, the amounts of drawings under the
Letter of Credit shall not have been repaid or refinanced in full on or before
the date five years after the Effective Date.

         "MIDWEST" has the meaning set forth in the Recitals.

         "MOODY'S" means Moody's Investors Service, a division of Dun &
Bradstreet Corporation, and its successors and assigns.

         "OWNER LESSOR" has the meaning set forth in the Recitals.

         "PARTICIPATION AGREEMENT" means the Participation Agreement [(T1)]
dated as of December 15, 1999 among Collins Holdings EME, LLC, Wilmington Trust
Company, as Owner Trustee of the Owner Lessor, the Owner Lessor, the Owner
Participant named therein, Edison Mission Midwest Holdings Co., Midwest, the
Bank, Bayerische Landesbank Girozentrale, Funding LLC and Citibank, N.A., as
Holder Representative, as the same may be amended, supplemented or otherwise
modified from time to time.

         "PERSON" means any natural person, corporation, partnership, limited
liability company, firm, association, trust, government, governmental agency or
any other entity, whether acting in an individual, fiduciary or other capacity.

         "PRICING GRID" means the pricing grid attached as ANNEX B.

         "REIMBURSEMENT OBLIGATIONS" has the meaning set forth in Section 2 of
the Agreement.


                                       3
<PAGE>

         "SECURITIZATION COMPANY" means CXC Incorporated.

         "S&P" means Standard & Poor's Ratings Services and its successors and
assigns.

         "UNITED STATES" or "U.S." means the United States of America.

         Section 1.2 USE OF DEFINED TERMS. Unless otherwise defined or the
context otherwise requires, terms for which meanings are provided in this Annex
A shall have such meanings when used in each other Annex, the Agreement and any
other notice and other communication delivered from time to time in connection
with this Agreement.






                                       4
<PAGE>


                                                                         ANNEX B
                                                      TO REIMBURSEMENT AGREEMENT


                                  PRICING GRID
<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------------
BASIS FOR PRICING(1)           LEVEL 1           LEVEL 2           LEVEL 3            LEVEL 4         LEVEL 5           LEVEL 6

                             DEBT RATING       DEBT RATING       DEBT RATING        DEBT RATING     DEBT RATING       DEBT RATING
                              AT LEAST:         LESS THAN         LESS THAN          LESS THAN       LESS THAN        LOWER THAN
                           BBB+ BY S&P AND       LEVEL 1            LEVEL 2           LEVEL 3         LEVEL 4           LEVEL 5
                           Baa1 BY MOODY'S    BUT AT LEAST:      BUT AT LEAST:     BUT AT LEAST:   BUT AT LEAST:
                                              BBB BY S&P AND    BBB- BY S&P AND    BB+ BY S&P AND  BB BY S&P AND
                                             Baa2 BY MOODY'S    Baa3 BY MOODY'S    Ba1 BY MOODY'S  Ba2 BY MOODY'S
-----------------------------------------------------------------------------------------------------------------------------------
<S>                            <C>               <C>               <C>               <C>             <C>               <C>
BASE RATE APPLICABLE            0 bps             0 bps             15 bps            62.5 bps        87.5 bps          100 bps
MARGIN
-----------------------------------------------------------------------------------------------------------------------------------
LIBOR APPLICABLE MARGIN        100 bps           125 bps            150 bps           225 bps         275 bps           325 bps
-----------------------------------------------------------------------------------------------------------------------------------
</TABLE>

         bps = basis points per annum
(1)      At any time the Debt Ratings are split between S&P and Moody's, the
         Pricing Level in which the lower rating falls should govern.


<PAGE>


                                                                       EXHIBIT A
                                                      TO REIMBURSEMENT AGREEMENT



                                     FORM OF
                          IRREVOCABLE LETTER OF CREDIT

                                  No. [______]

                    BAYERISCHE LANDESBANK INTERNATIONAL S.A.

                                December 15, 1999




Collins Trust I
  as Owner Lessor
c/o Wilmington Trust Company
Rodney Square North
1100 North Market Street
Wilmington, Delaware  19890-0001

         Attn:  Corporate Trust Administration

Ladies and Gentlemen:

         1. The Bank hereby establishes, at the request and for the account of
the Account Party, in favor of the Beneficiary to support the certain
obligations of the Account Party to Collins Holdings under the Facility Sublease
and the correlative obligations of Collins Holdings to Owner Lessor under the
Facility Lease, this Irrevocable Letter of Credit in the maximum amount of three
million eight hundred seventy thousand U.S. Dollars and zero Cents
(U.S.$3,870,000.00), effective immediately and expiring on the Expiration Date.

         2. As used herein, the following terms have the following meanings:

         A. "ACCOUNT PARTY" means Midwest Generation, LLC.

                  B. "APA" means the Asset Purchase Agreement dated as of
         December 15, 1999 (as the same may be amended, supplemented or
         otherwise modified from time to time) among Midwest Funding LLC, CXC
         Incorporated (the "SECURITIZATION COMPANY"), Citibank, N.A., as agent,
         each of the financial institutions party thereto as "Purchasers" (the
         "PURCHASERS") and Citicorp North America, Inc., as operating agent for
         the Securitization Company and as RCE Agent.

                  C. "BANK" means Bayerische Landesbank International S.A.

                  D. "BENEFICIARY" means (i) initially, the Owner Lessor and
         (ii) after giving effect to the transfer and assignment by the Owner
         Lessor of all of its right, title and interest in, to and under this
         Letter of Credit as collateral security for the obligations of the
         Owner Lessor under, and as provided in, the RCE Reimbursement Agreement
         on the


<PAGE>

                                       2

         date hereof to Bayerische Landesbank Girozentrale, Bayerische
         Landesbank Girozentrale.

                  E. "BUSINESS DAY" means any day except a Saturday, Sunday or
         legal holiday in New York City, New York or a day on which banks in New
         York City, New York, Wilmington, Delaware or Luxembourg are authorized
         or required by law or executive order to close.

                  F. "COLLINS HOLDINGS" means Collins Holdings EME, LLC.

                  G. "EXPIRATION DATE" means December 15, 2004.

                  H. "FACILITY LEASE" means the Facility Lease Agreement (TI),
         dated as of December 15, 1999, between the Owner Lessor and Collins
         Holdings, as the same may be from time to time amended, supplemented,
         amended and restated, or otherwise modified and in effect from time to
         time.

                  I. "FACILITY SUBLEASE" means, the Facility Sublease Agreement
         (TI), dated as of December 15, 1999 between Collins Holdings and the
         Account Party, as the same may be from time to time amended,
         supplemented, amended and restated, or otherwise modified and in effect
         from time to time.

                  J. "LEASE DEFAULT" means, with respect to the Facility Lease,
         any event which with the passage of time or the giving of notice would
         become a Lease Event of Default thereunder.

                  K. "LEASE EVENT OF DEFAULT" means, with respect to the
         Facility Lease, a Lease Event of Default as such term is defined
         thereunder.

                  L. "LETTER OF CREDIT" means this Irrevocable Letter of Credit
         No. [_________] issued by the Bank.

                  M. "MAXIMUM AMOUNT" means three million eight hundred seventy
         thousand U.S. Dollars and zero Cents (U.S.$3,870,000.00).

                  N. "OWNER LESSOR" means Collins Trust (I), a Delaware business
         trust, together with its successor and assigns.

                  O. "RATING AGENCY" means each of Moody's Investors Service,
         Inc. and Standard & Poor's Ratings Services, a division of The McGraw
         Hill Companies, Inc.

                  P. "RCE AGENT" means Citicorp North America, Inc., a Delaware
         corporation, in its capacity as agent for the Purchasers and the
         Securitization Company.

                  Q. "RCE REIMBURSEMENT AGREEMENT" means the Reimbursement
         Agreement dated as of December 15, 1999 between the Owner Lessor and
         Bayerische Landesbank Girozentrale.

                  R. "RCE LETTER OF CREDIT" shall mean that certain Irrevocable
         Letter of Credit issued by Bayerische Landesbank Girozentrale in favor
         of the RCE Agent for the account of the Owner Lessor.

         3. Partial drawings are permitted hereunder. The Bank hereby
irrevocably authorizes the Beneficiary to draw on the Bank, from time to time,
in accordance with the terms


<PAGE>

                                       3

and conditions hereinafter set forth, in amounts not exceeding, in the
aggregate, the Maximum Amount. The Bank shall pay such drawings with its own
funds. Except as expressly stated herein, this undertaking is not subject to any
agreement, condition or qualification.

         4. Only the Beneficiary may make drawings under this Letter of Credit.
Upon payment by the Bank of one or more drawings that, in the aggregate, are
equal to the Maximum Amount, the Bank shall be fully discharged from its
obligations under this Letter of Credit, and the Bank shall not thereafter be
obligated to make any further payment under this Letter of Credit to the
Beneficiary or to any other person.

         5. Funds under this Letter of Credit will be made available to the
Beneficiary against the Beneficiary's certificate or certificates signed by the
Owner Lessor in the form of Annex 1 hereto, appropriately completed, and may be
delivered by telecopy transmission to telecopy number (00352) 42434-3399, or
delivered in person or by mail or courier to the Bank's offices located at 3,
Rue Jean Monnet, L-2180 Luxembourg or at any other office in New York City that
may be designated by the Bank in a written notice delivered to the Beneficiary.

         6. Each such certificate referred to in paragraph 5 above shall be
dated on or within three Business Days prior to the date of presentation. Upon
receipt by the Bank of an appropriately completed certificate in conformity with
the terms and conditions of this Letter of Credit, at or before 5:00 p.m., New
York City time, on or before the Expiration Date, the Bank will honor the same
(to the extent required by this Letter of Credit) in accordance with the payment
instructions of the Beneficiary to the Bank by 4:00 p.m., New York City time, on
the Business Day following receipt of such certificate by the Bank; PROVIDED
that if such certificate is received prior to 11:00 a.m., New York City time, on
a Business Day, the Bank shall make its payment in immediately available funds
by 4:00 p.m., New York City time, on such Business Day.

         7. This Letter of Credit shall automatically terminate on the
Expiration Date; PROVIDED, HOWEVER, that if the Bank's business is interrupted
or suspended on the Expiration Date for any reason, this Letter of Credit shall
automatically terminate on the date 21 days immediately after the Bank's
resumption of business.

         8. THIS LETTER OF CREDIT SHALL BE SUBJECT TO AND GOVERNED BY THE
UNIFORM CUSTOMS AND PRACTICE FOR DOCUMENTARY CREDITS (1993 REVISION),
(INTERNATIONAL CHAMBER OF COMMERCE, PARIS, FRANCE PUBLICATION NO. 500) (AND ANY
SUCCESSOR PUBLICATIONS).

         9. The right, title and interest of the Beneficiary in, to and under
this Letter of Credit are transferable and assignable in their entirety (but not
in part) to any transferee or assignee designated by the Beneficiary. The Owner
Lessor as original beneficiary has transferred and assigned all of its right,
title and interest in, to and under this Letter of Credit to Bayerische
Landesbank Girozentrale having an address at 560 Lexington Avenue, New York, NY
10022 as collateral security for the Owner Lessor's obligations under the RCE
Reimbursement Agreement.

         10. Communications with respect to this Letter of Credit shall be in
writing and shall be addressed to the Bank at 3, Rue Jean Monnet, L-2180
Luxembourg (or any other office in New York City which may be designated by the
Bank in a written notice delivered to the Beneficiary, and the Account Party),
specifically referring to the number of this Letter of Credit.



<PAGE>

                                       4


         11. This Letter of Credit sets forth in full the Bank's undertakings,
and the Bank's undertakings hereunder shall not in any way be modified, amended,
amplified or limited by reference to any document, instrument or agreement
referred to herein except for the certificates referred to herein, and any such
reference shall not be deemed to incorporate herein by reference any document,
instrument or agreement except for such certificates.

                                          Very truly yours,

                                          BAYERISCHE LANDESBANK
                                          INTERNATIONAL S.A.


                                          By:
                                              ----------------------------------
                                                 Name:
                                                 Title:


                                          By:
                                              ----------------------------------
                                                 Name:
                                                 Title:




<PAGE>

                                                                      ANNEX 1 TO
                                                                LETTER OF CREDIT



                            BENEFICIARY'S CERTIFICATE


Re: Irrevocable Letter of Credit No. [_______________] (the "Letter of Credit")
dated December 15, 1999, issued by Bayerische Landesbank International S.A. at
the request and for the account of the Account Party identified therein.

         Reference is made to the Letter of Credit. Any capitalized term used
herein and not defined herein has its respective meaning as set forth in the
Letter of Credit.

         The Beneficiary hereby demands payment in the amount of
U.S.$____________ ([insert amount in words)] U.S. Dollars. This is a drawing
under the Letter of Credit. The Beneficiary hereby certifies to the Bank:

         (1)      The Beneficiary is entitled to draw under this Letter of
                  Credit the amount specified in this Certificate because [both
                  (i) a drawing against the RCE Letter of Credit has been made
                  in an amount at least equal to the amount of the drawing
                  requested hereby and (ii) a Lease Default that is a payment or
                  bankruptcy default has occurred and is continuing.] [or]
                  [(A)(i) the rating of the unsecured debt securities of
                  Bayerische Landesbank Girozentrale shall be downgraded below
                  [P-1 by Moody's or the higher of A-1] or the then current
                  rating of the Securitization Company's commercial paper by
                  S&P, or (ii) Bayerische Landesbank Girozentrale has been
                  mentioned with negative implications in "CreditWatch" by S&P
                  or a similar publication list by S&P or Moody's and the
                  Account Party has failed to arrange for the issuance of a
                  substitute irrevocable letter of credit in the then available
                  amount under this Letter of Credit by a bank whose unsecured
                  debt securities are rated by the Rating Agencies as high as
                  the ratings stated in clause (i) above and which is not a bank
                  with respect to which clause (ii) above would be applicable
                  and (B) a drawing against the RCE Letter of Credit has been
                  made.] *Delete as applicable.

         (2)      The amount of the drawing made by this Certificate, together
                  with all other amounts previously drawn by the Beneficiary
                  under the Letter of Credit, does not exceed the Maximum
                  Amount.

         The Beneficiary hereby requests that payment under the Letter of Credit
by the Bank be made by wire transfer of federal funds to the Beneficiary's
Account No. ______ at [Name of Bank] in [Name of City and State in the United
States].



<PAGE>


         IN WITNESS WHEREOF, the Beneficiary has executed and delivered this
Certificate as of the ____ day of ___________, _____

                                         [BENEFICIARY]


                                          By:
                                              ----------------------------------
                                                Name:
                                                Title: