<PAGE>



               FOURTH AMENDMENT TO REVOLVING CREDIT AGREEMENT      EXHIBIT 10.12

                          Dated as of February 16, 2001

This Amendment, dated as of February 16, 2001, is entered into between SECOND
BANCORP INCORPORATED, a corporation formed under the laws of the State of Ohio
("Borrower"), and THE NORTHERN TRUST COMPANY, an Illinois banking corporation
having its principal office at 50 South LaSalle Street, Chicago, Illinois 60675
("Lender").

                                    RECITALS:

        A.     Borrower and Lender have entered into a Revolving Credit
Agreement dated as of September 15, 1995, a First Amendment thereto dated as of
March 11, 1997, a Second Amendment thereto dated as of February 17, 1999 and a
Third Amendment thereto dated as of February 16, 2000 (said Revolving Credit
Agreement, as so amended, shall hereinafter be referred to as the "Agreement";
the terms defined in the Agreement and not otherwise defined herein shall be
used herein as 'defined' in the Agreement).

        B.     Borrower and Lender wish to amend certain provisions of the
Agreement.

        C.     Therefore, the parties hereto agree as follows:

                        SECTION I AMENDMENTS TO AGREEMENT

SECTION 1.1 NOTE. Section 1.2 of the Agreement is hereby amended as of the date
hereof by deleting the date "February 16, 2001 " in the eleventh and twelfth
lines thereof and replacing such date with "April 3, 2002."

SECTION 1.2 FORM OF PROMISSORY NOTE. Exhibit A to the Agreement is hereby
amended as of the date hereof to be in the form set forth as Exhibit A hereto.

                    SECTION 2 REPRESENTATIONS AND WARRANTIES

To induce Lender to enter into this Amendment, Borrower represents and warrants
to Lender that:

SECTION 2.1 AUTHORIZATION; NO CONFLICT. The execution and delivery of this
Amendment and the Replacement Note (as hereinafter defined), the borrowings
under the Agreement, as amended hereby, and the performance by Borrower of its
obligations under the Agreement, as amended hereby, and under the Replacement
Note: (a) are within Borrower's powers-, (b) have been authorized by all
necessary corporate action; (c) have received any and all necessary governmental
approval; and (d) do not and will not contravene or conflict with any provision
of law or charter or by-laws of Borrower or any agreement affecting Borrower or
its property.

SECTION 2.2 VALIDITY AND BINDING EFFECT. The Agreement, as amended hereby, is,
and the Replacement Note when duly executed and delivered will be, a legal,
valid and binding obligation of Borrower, enforceable against Borrower in
accordance with its terms, except as enforceability may be limited by
bankruptcy, insolvency or other similar laws of general application affecting
the enforcement of creditors' rights or by general principles of equity limiting
the availability of equitable remedies.

SECTION 3.1 DOCUMENTATION. Lender shall have received all of the following
promptly upon the execution and delivery hereof, each duly executed and dated
the date hereof or such other date as is satisfactory to Lender, in form and
substance satisfactory to Lender and its counsel, at the expense of Borrower,
and in such number of signed counterparts as Lender may request (except for the
Replacement Note, of which only the original shall be signed):

        (a) Replacement Note. A promissory note of Borrower (the "Replacement
Note"), substantially in the form set forth as Exhibit A hereto.









                                       73
<PAGE>



Upon receipt of the Replacement Note, Lender will record the aggregate unpaid
principal amount of the Replacement Note dated February 16, 2000 (the "Prior
Note") of Borrower issued under the Agreement in its records or, at its option,
on any schedule attached to the Replacement Note as the aggregate unpaid
principal amount of the Replacement Note. Thereafter, all references in the
Agreement and any and all instruments or documents provided for therein or
delivered or to be delivered thereunder or in connection therewith to the Prior
Note shall be deemed references to the Replacement Note.

        (b) Resolution; Certificate of Incumbency. A copy of a resolution of the
Board of Directors of Borrower authorizing or ratifying the execution and
delivery of this Amendment and the Replacement Note and the performance of the
Agreement, as amended hereby, and the Replacement Note, certified by an
appropriate officer of Borrower, together with a certificate of an appropriate
officer of Borrower, certifying the names of the officer(s) of Borrower
authorized to sign this Amendment, the Replacement Note and all other documents
or certificates to be delivered hereunder, together with a sample of the true
signatures of each such person (Lender may conclusively rely on such certificate
until formally advised by a like certificate of any changes therein).

        (c) Governing Documents. A certificate signed by an appropriate officer
of Borrower to the effect that there have been no amendments to the Articles of
Incorporation or the By-laws of Borrower since September 15, 1995 (or, if there
have been any such amendments. copies thereof, certified by an appropriate
officer of Borrower).


        (d) Certificate of No Default. A certificate signed by an appropriate
officer of Borrower to the effect that: (i) as at the date hereof, no Event of
Default or Unmatured Event of Default has occurred and is continuing; and (ii)
the representations and warranties of Borrower contained in the Agreement and
this Amendment are true and correct as at the date hereof as though made on that
date, except for such changes as are. specifically permitted under the
Agreement.

        (e) Other. Such other documents and certificates as Lender may
reasonably request.

SECTION 3.2 REPRESENTATIONS AND WARRANTIES TRUE; NO DEFAULT.

        (a) Representations and Warranties True. At the date hereof, Borrower's
representations and warranties set forth in the Agreement and this Amendment
shall be true and correct as though made on such date, except for such changes
as are specifically permitted under the Agreement.

                             SECTION 4 MISCELLANEOUS

This Amendment, the Replacement Note and any other document or instrument
executed in connection herewith shall be governed by and construed in accordance
with the internal laws of the State of Illinois, and shall be deemed to have
been executed in the State of Illinois. Unless the context requires otherwise,
wherever used herein the singular shall include the plural and vice versa, and
the use of one gender shall also denote the other. Captions herein are for
convenience of reference only and shall not define or limit any of the terms or
provisions hereof. This Amendment shall be binding upon and inure to the benefit
of Borrower, Lender and their respective successors and assigns, except that
Borrower may not transfer or assign any of its rights or interest hereunder
without the prior written consent of Lender. Borrower agrees to pay upon demand
up to $2,000 of the expenses (including without limitation attorneys' fees and
legal costs and expenses) incurred or paid by Lender in connection with the
preparation of this Amendment, the Replacement Note and any other document or
instrument to be delivered in connection herewith. Except as amended hereby, the
Agreement shall remain in full force and effect and is hereby ratified and
confirmed in all respects. Each reference in the Agreement to "this Amendment,"
"hereunder," "hereof," or words of like import, and each reference to the
Agreement in any and all instruments or documents provided for in the Agreement
or delivered or to be delivered thereunder or in connection therewith, shall,
except where the context otherwise requires, be deemed a reference to the
Agreement as amended hereby.




                                       74
<PAGE>


IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be executed
by their respective officers thereunto duly authorized as of the date first
written above.

                                  SECOND BANKCORP INCORPORATED

                                  By:   /s/  David L. Kellerman
                                        ------------------------------

                                  Title:      Treasurer
                                          ----------------------------

                                  THE NORTHERN TRUST COMPANY

                                  By:
                                        ------------------------------

                                  Title:
                                        ------------------------------























                                       75