<PAGE>

                      Ninth Amendment To Credit Agreement

Harris Trust and Savings Bank
Chicago, Illinois

Ladies and Gentlemen:

     Reference is hereby made to that certain Credit Agreement dated as of May
22, 1996, as amended (the "Credit Agreement"), between the undersigned, MAF
Bancorp, Inc., a Delaware corporation (the "Company") and you (the "Lender").
All capitalized terms used herein without definition shall have the same
meanings herein as such terms have in the Credit Agreement.

     The Company has requested the Lender amend the Credit Agreement by
increasing the Revolving Credit Commitment to $25,000,000, extending the
Revolving Credit Termination Date to May 31, 2001, amending the remaining Term
Loan principal repayment schedule, deleting the Treasury Rate interest option,
amending the interest rate due on the Domestic Rate Portion, amending the
Interest Periods for LIBOR Portions, deleting the commitment fee and adding a
facility fee in lieu thereof, amending the Adjusted Net Worth covenant, and
amending the Adjusted Net Income covenant, and the Lender is willing to do so
under the terms and conditions set forth in this agreement (herein, the
"Amendment").

1.   Amendments.

     Upon your acceptance hereof in the space provided for that purpose below,
the Credit Agreement shall be and hereby is amended as follows:

          1.1  The second, third and fourth paragraphs of Section 1.4 of the
     Credit Agreement shall be amended and restated in their entireties to read
     as follows:

          The original principal amount of the Term Loan was $35,000,000, of
          which $29,900,000 remains outstanding and unpaid on April 20, 2000.
          The Company hereby agrees to repay the balance of the Term Loan in the
          amounts and on the dates set fourth below:
<TABLE>
<CAPTION>
                      A                                    B
                 Payment Date                     Scheduled Principal
                                                  Payment on Term Note
                 <S>                              <C>
                  12/31/2000                          $   500,000
                  12/31/2001                          $ 1,500,000
                  12/31/2002                          $ 9,200,000
                  12/31/2003                          $18,700,000 or such
                                                  lesser amount representing the
                                                  remaining principal balance of
                                                  the Term Loan
</TABLE>
<PAGE>

          1.2  Section 2.1 of the Credit Agreement shall be amended and
     restated in its entirety to read as follows:

                Section 2.1.  Interest Rate Options.

                (a) Portions. Subject to the terms and conditions of this
          Section 2, portions of the principal indebtedness evidenced by the
          Notes (all of the indebtedness evidenced by Notes of the same type
          bearing interest at the same rate for the same period of time being
          hereinafter referred to as a "Portion") may, at the option of the
          Company, bear interest with reference to the Domestic Rate ("Domestic
          Rate Portions") or with reference to the Adjusted LIBOR ("LIBOR
          Portions"). Subject to the terms and conditions of this Section 2, the
          Domestic Rate Portion or LIBOR Portions of Notes of the same type may
          be converted from time to time from one basis to the other. All of the
          indebtedness evidenced by a Note which is not part of a LIBOR Portion
          shall constitute a single Domestic Rate Portion applicable to such
          Note. All of the indebtedness evidenced by a Note which bears interest
          with reference to a particular Adjusted LIBOR for a particular
          Interest Period shall constitute a single LIBOR Portion applicable to
          such Note. There shall not be more than five LIBOR Portions applicable
          to the Revolving Credit Note outstanding at any one time. There shall
          be not more than seven LIBOR Portions applicable to the Term Note
          outstanding at any one time. Anything contained herein to the contrary
          notwithstanding, the obligation of the Lender to create, continue or
          effect by conversion any LIBOR Portion shall be conditioned upon the
          fact that at the time no Default or Event of Default shall have
          occurred and be continuing. The Company hereby promises to pay
          interest on each Portion at the rates and times specified in this
          Section 2.

                (b) Domestic Rate Portion. Each Domestic Rate Portion shall bear
          interest at the rate per annum determined equal to the Domestic Rate
          as in effect from time to time minus (but not below zero) 0.5% per
          annum, provided that if a Domestic Rate Portion or any part thereof is
          not paid when due (whether by lapse of time, acceleration or
          otherwise) such Portion shall bear interest, whether before or after
          judgment, until payment in full of the amount then due at the rate per
          annum determined by adding 2% to the interest rate which would
          otherwise be applicable thereto from time to time. Interest on each
          Domestic Rate Portion shall be payable quarterly in arrears on the
          last day of each March, June, September and December in each year and
          at maturity of the applicable Note, and interest after maturity
          (whether by lapse of time, acceleration or otherwise) shall be due and
          payable upon demand. Any change in the interest rate on the Domestic
          Rate
                                      -2-
<PAGE>

          Portions resulting from a change in the Domestic Rate shall be
          effective on the date of the relevant change in the Domestic Rate.

                (c) LIBOR Portions. Each LIBOR Portion shall bear interest for
          each Interest Period selected therefor at a rate per annum determined
          by adding 1% to the Adjusted LIBOR for such Interest Period, provided
          that if any LIBOR Portion is not paid when due (whether by lapse of
          time, acceleration or otherwise) such Portion shall bear interest,
          whether before or after judgment, until payment in full of the amount
          then due through the end of the Interest Period then applicable
          thereto at the rate per annum determined by adding 2% to the interest
          rate which would otherwise be applicable thereto, and effective at the
          end of such Interest Period such LIBOR Portion shall automatically be
          converted into and added to the applicable Domestic Rate Portion and
          shall thereafter bear interest at the interest rate applicable to such
          Domestic Rate Portion. Interest on each LIBOR Portion shall be due and
          payable on the last day of each Interest Period applicable thereto,
          and interest after maturity (whether by lapse of time, acceleration or
          otherwise) shall be due and payable upon demand. The Company shall
          notify the Lender on or before 11:00 a.m. (Chicago time) on the third
          Business Day preceding the end of an Interest Period applicable to a
          LIBOR Portion whether such LIBOR Portion is to continue as a LIBOR
          Portion, in which event the Company shall notify the Lender of the new
          Interest Period selected therefor, and in the event the Company shall
          fail to so notify the Lender, such LIBOR Portion shall automatically
          be converted into and added to the applicable Domestic Rate Portion as
          of and on the last day of such Interest Period.

          1.3   Section 2.4 of the Credit Agreement shall be amended and
     restated in its entirety to read as follows:

                Section 2.4. Manner of Rate Selection. The Company shall notify
          the Lender by 11:00 a.m. (Chicago time) at least three Business Days
          prior to the date upon which the Company requests that any LIBOR
          Portion be created or that any part of the applicable Domestic Rate
          Portion be converted into a LIBOR Portion (each such notice to specify
          in each instance the amount thereof and the Interest Period selected
          therefor). If any request is made to convert a LIBOR Portion into the
          relevant Domestic Rate Portion hereunder, such conversion shall only
          be made so as to become effective as of the last day of the Interest
          Period applicable thereto. All requests for the creation, continuance
          and conversion of LIBOR Portions under this Agreement shall be
          irrevocable. Such requests may be written or oral and the Lender is
          hereby authorized to honor telephonic requests for creations,
          continuances

                                      -3-
<PAGE>

          and conversions received by it from any person the Lender in good
          faith believes to be an Authorized Representative without the
          necessity of independent investigation, the Company hereby
          indemnifying the Lender from any liability or loss ensuing from so
          acting.

          1.4   Section 2.9 of the Credit Agreement shall be amended and
     restated in its entirety to read as follows:

                Section 2.9.  Intentionally Deleted.

          1.5  Section 3.1(a) of the Credit Agreement shall be amended and
     restated in its entirety to read as follows:

                Section 3.1. Fees. (a) Revolving Credit Facility Fee. For the
          period from and including April 1, 2000, to but not including the
          Revolving Credit Termination Date, the Company shall pay to the Lender
          a facility fee at the rate of .09% per annum (computed on the basis of
          a year of 360 days for the actual number of days elapsed) on the
          average daily Revolving Credit Commitment in effect during such time
          (whether or not in use). Such facility fee shall be payable quarterly
          in arrears on the last day of each March, June, September, and
          December in each year (commencing June 30, 2000) and on the Revolving
          Credit Termination Date unless the Revolving Credit Commitment is
          terminated in whole on an earlier date, in which event the facility
          fee for the period to the date of such termination in whole shall be
          paid on the date of such termination.

          1.6   Section 3.2 of the Credit Agreement shall be amended and
     restated in its entirety to read as follows:

                Section 3.2.  Voluntary Prepayments.  The Company shall have the
          privilege of prepaying the Revolving Credit Loans and the Term Loan in
          whole or in part (but if in part, then (i) if such Loans constitute
          part of a Domestic Rate Portion, in an amount not less than $100,000,
          (ii) if such Loan constitutes part of a LIBOR Portion, in an amount
          not less than $1,000,000, and (iii) in each case, in an amount such
          that the minimum amount required for a borrowing of Revolving Credit
          Loans or for a LIBOR Portion of the relevant Loans pursuant to
          Sections 1.2 and 2.2 hereof remains outstanding) at any time upon 1
          Business Day prior notice to the Lender (such notice if received
          subsequent to 2:00 p.m. (Chicago time) on a given day to be treated as
          though received at the opening of business on the next Business Day),
          by paying to the Lender the principal amount to be prepaid and (i) if
          such a prepayment prepays the Term Note in whole or in part,

                                      -4-
<PAGE>

          accrued interest thereon to the date of prepayment, (ii) if such a
          prepayment prepays the Revolving Credit Note in full and is
          accompanied by the termination in whole of the Revolving Credit
          Commitment, accrued interest and facility fees thereon to the date of
          prepayment, and (iii) any amounts due to the Lender under Section 2.8
          hereof.

          1.7  The definition of "Fixed Rate Portions" appearing in Section
     4.1 of the Credit Agreement shall be amended and restated in its entirety
     to read as follows:

          "Fixed Rate Portions" means and includes the LIBOR Portions.

          1.8  The first paragraph of the definition of "Interest Period"
     appearing in Section 4.1 of the Credit Agreement shall be amended and
     restated in its entirety to read as follows:

          "Interest Period" means, with respect to any LIBOR Portion, the period
          commencing on, as the case may be, the creation, continuation or
          conversion date with respect to such LIBOR Portion and ending 1, 2, 3,
          6 or 12 months thereafter as selected by the Company in its notice as
          provided herein; provided that, all of the foregoing provisions
          relating to Interest Periods are subject to the following:

          1.9  The definition of "Revolving Credit Commitment" appearing in
     Section 4.1 of the Credit Agreement shall be amended and restated in its
     entirety to read as follows:

          "Revolving Credit Commitment" means $25,000,000, as such amount may be
          reduced pursuant hereto.

          1.10  The definition of "Revolving Credit Termination Date" appearing
     in Section 4.1 of the Credit Agreement shall be amended and restated in its
     entirety to read as follows:

          "Revolving Credit Termination Date" means May 31, 2001, or such
          earlier date on which the Revolving Credit Commitment is terminated in
          whole pursuant to Section 3.3, 3.4, 8.2 or 8.3 hereof.

          1.11  The definition of "Treasury Rate" appearing in Section 4.1 of
     the Credit Agreement shall be deleted in its entirety.

          1.12  The definition of "Treasury Rate Portions" appearing in Section
     4.1 of the Credit Agreement shall be deleted in its entirety.

          1.13  Section 7.10 of the Credit Agreement shall be amended and
     restated in its entirety to read as follows:

                                      -5-
<PAGE>

                Section 7.10.  Adjusted Net Worth.  The Company shall, as of the
          last day of each fiscal quarter of the Company, maintain Adjusted Net
          Worth of the Company and its Subsidiaries determined on a consolidated
          basis in an amount not less than $200,000,000.

          1.14  Section 7.11 of the Credit Agreement shall be amended and
     restated in its entirety to read as follows:

                Section 7.11.  Adjusted Net Income.  As of the last day of each
          fiscal year of the Company, the Company shall have Adjusted Net Income
          for the year then ended of not less than $30,000,000.

          1.15  Exhibit A to the Credit Agreement shall be amended in its
     entirety, and as amended shall be restated to read as set forth on Exhibit
     A attached hereto.

2.   Conditions Precedent.

     The effectiveness of this Amendment is subject to the satisfaction of all
of the following conditions precedent:

          2.1  The Company and the Lender shall have executed and delivered
     this Amendment, and the Company shall have executed and delivered to the
     Lender a replacement Revolving Credit Note in the form attached hereto as
     Exhibit A.

          2.2  The Company shall have paid through March 31, 2000, all unused
     commitment fees due under the Credit Agreement prior to giving effect to
     this Amendment.

          2.3  Legal matters incident to the execution and delivery of this
     Amendment shall be satisfactory to the Lender and its counsel.

3.   Miscellaneous.

     3.1  Except as specifically amended herein, the Credit Agreement shall
continue in full force and effect in accordance with its original terms.
Reference to this Amendment need not be made in the Credit Agreement, the Notes,
or any other instrument or document executed in connection therewith, or in any
certificate, letter or communication issued or made pursuant to or with respect
to the Credit Agreement, any reference in any of such items to the Credit
Agreement being sufficient to refer to the Credit Agreement as amended hereby.

     3.2  The Company agrees to pay on demand all costs and expenses of or
incurred by the Lender in connection with the negotiation, preparation,
execution, and delivery of this Amendment in excess of $3,000, including the
fees and expenses of counsel for the Lender.

     3.3  This Amendment may be executed in any number of counterparts, and by
the different parties on different counterpart signature pages, all of which
taken together shall

                                      -6-
<PAGE>

constitute one and the same agreement. Any of the parties hereto may execute
this Amendment by signing any such counterpart and each of such counterparts
shall for all purposes be deemed to be an original. This Amendment shall be
governed by the internal laws of the State of Illinois.

                           [Signature Page to Follow]

                                      -7-
<PAGE>

     This Ninth Amendment to Credit Agreement is entered into and effective as
of May 5, 2000.

                                 MAF BANCORP, INC.


                                 By    /s/ Jerry Weberling
                                   --------------------------------------
                                   Name  Jerry Weberling
                                       ----------------------------------
                                   Title  Executive Vice President & CFO
                                        ---------------------------------

     Accepted and agreed to in Chicago, Illinois as of the date and year last
above written.


                                 HARRIS TRUST AND SAVINGS BANK

                                 By    /s/ Michael S. Cameli
                                   --------------------------------------
                                   Name  Michael S. Cameli
                                       ----------------------------------
                                   Title  Vice President
                                        ---------------------------------

                                      -8-
<PAGE>

                                   Exhibit A

                               MAF Bancorp, Inc.
                             Revolving Credit Note

                                                               Chicago, Illinois
$25,000,000                                                          May 5, 2000

     On the Revolving Credit Termination Date, for value received, the
undersigned, MAF Bancorp, Inc., a Delaware corporation (the "Company"), hereby
promises to pay to the order of Harris Trust and Savings Bank (the "Lender"), at
the principal office of the Lender in Chicago, Illinois, the principal sum of
(i) Twenty Five Million and no/100 Dollars ($25,000,000), or (ii) such lesser
amount as may at the time of the maturity hereof, whether by acceleration or
otherwise, be the aggregate unpaid principal amount of all Revolving Credit
Loans owing from the Company to the Lender under the Revolving Credit provided
for in the Credit Agreement hereinafter mentioned.

     This Note is issued in substitution and replacement for, and evidences the
indebtedness evidenced by, the Revolving Credit Note of the Company dated April
30, 1999, in the face principal amount of $20,000,000, and, in addition,
evidences additional loans constituting part of a "Domestic Rate Portion" and
"LIBOR Portions" as such terms are defined in that certain Credit Agreement
dated as of May 22, 1996, as amended, between the Company and the Lender (said
Credit Agreement, as the same may be amended, modified or restated from time to
time, being referred to herein as the "Credit Agreement") made and to be made to
the Company by the Lender under the Revolving Credit provided for under the
Credit Agreement, and the Company hereby promises to pay interest at the office
described above on each loan evidenced hereby at the rates and at the times and
in the manner specified therefor in the Credit Agreement.

     Each loan made under the Revolving Credit against this Note, any repayment
of principal hereon, the status of each such loan from time to time as part of
the Domestic Rate Portion or a LIBOR Portion and, in the case of any LIBOR
Portion, the interest rate and Interest Period applicable thereto shall be
endorsed by the holder hereof on a schedule to this Note or recorded on the
books and records of the holder hereof (provided that such entries shall be
endorsed on a schedule to this Note prior to any negotiation hereof).  The
Company agrees that in any action or proceeding instituted to collect or enforce
collection of this Note, the entries so endorsed on a schedule to this Note or
recorded on the books and records of the holder hereof shall be prima facie
evidence (absent manifest error) of the unpaid principal balance of this Note,
the status of each such loan from time to time as part of the Domestic Rate
Portion or a LIBOR Portion, and, in the case of any LIBOR Portion, the interest
rate and Interest Period applicable thereto.

     This Note is issued by the Company under the terms and provisions of the
Credit Agreement, and this Note and the holder hereof are entitled to all of the
benefits and security provided for thereby or referred to therein, to which
reference is hereby made for a statement thereof.  This Note may be declared to
be, or be and become, due prior to its expressed maturity, voluntary prepayments
may be made hereon, and certain prepayments are required to be made hereon, all
in the events, on the terms and with the effects provided in the Credit
Agreement.  All
<PAGE>

capitalized terms used herein without definition shall have the
same meanings herein as such terms are defined in the Credit Agreement.

     The Company hereby promises to pay all costs and expenses (including
attorneys' fees) suffered or incurred by the holder hereof in collecting this
Note or enforcing any rights in any collateral therefor.  The Company hereby
waives presentment for payment and demand.  This Note shall be construed in
accordance with, and governed by, the internal laws of the State of Illinois
without regard to principles of conflicts of laws.


                                  MAF Bancorp, Inc.

                                  By /s/ Jerry Weberling
                                     -----------------------------------------
                                      Jerry Weberling,   Executive. V.P. & CFO
                                    ------------------------------------------
                                    (Print or Type Name)        (Title)

                                      -2-