<PAGE>

                                                                   Exhibit 10.13


                     FIRST AMENDMENT TO AMENDED AND RESTATED

                               CONTINUING GUARANTY

         This First Amendment to Amended and Restated Continuing Guaranty
Agreement is entered into as of the 4th day of June, 2003 by and among Education
Lending Group, Inc., a Delaware corporation (formerly known as Direct III
Marketing, Inc.) ("Guarantor") and Fifth Third Bank, an Ohio banking
corporation, for itself and as agent for any affiliate of Fifth Third Bancorp
("Beneficiary").

         WHEREAS, Guarantor and Beneficiary are parties to an Amended and
Restated Continuing Guaranty Agreement, dated as of March 26, 2002 (the
"Guaranty Agreement"); and

         WHEREAS, Guarantor and Beneficiary now desire to enter into this First
Amendment to Amended and Restated Continuing Guaranty Agreement to recognize the
change of the name of Direct III Marketing, Inc. to Education Lending Group,
Inc. and the change of name of Grad Partners, Inc. to Education Lending
Services, Inc. and to reflect an increase in the amount guaranteed by the
Guaranty Agreement.

         NOW THEREFORE, in consideration of the mutual promises and covenants
set forth herein and for other good and valuable consideration, the receipt and
adequacy of which are hereby acknowledged, intending to be legally bound, the
parties hereto agree as follows:

         1. Construction. All capitalized terms used herein, unless otherwise
defined herein, shall have the meaning given to such terms in the Guaranty
Agreement. By the execution of this Amendment, the parties hereby ratify,
confirm and approve in all respects the Guaranty Agreement and all its
provisions. Except as expressly amended hereby, the Guaranty Agreement shall
continue in full force and effect in accordance with its terms.

         2. Name Change. The Guaranty Agreement is hereby amended by
substituting (a) Education Lending Group, Inc. for Direct III Marketing, Inc.,
(b) Education Lending Services, Inc. for Grad Partners, Inc. and (c) and ELS for
Grad Partners wherever such terms appear.

         3. Introductory Information. The Guaranty Agreement is hereby amended
by deleting the first WHEREAS clause in its entirety and replacing it with the
following:

            WHEREAS, Beneficiary has agreed to extend credit and financial
accommodations to Education Lending Services, Inc., a Delaware corporation
(formerly known as Grad Partners, Inc.) ("ELS"), and to Student Loan Xpress,
Inc., a Delaware corporation ("Xpress") (each of ELS and Xpress hereinafter,
from time to time, a "Borrower", and collectively, from time to time, the
"Borrowers") pursuant to that certain Second Amended and Restated Credit
Agreement dated as of March 26, 2002, as amended from time to time, by and among
ELS, Xpress and Beneficiary, together with

<PAGE>

the Revolving Notes dated as of September 17, 2001 and March 26, 2002, as
amended from time to time, executed by ELS and Xpress respectively, each for a
maximum principal amount of $19,000,000, less the amount borrowed by the other
Borrower, and each made payable to the order of Beneficiary (the "Notes"), and
all agreements, instruments and documents executed or delivered in connection
with any of the foregoing or otherwise related thereto (together with any
amendments, modifications, or restatements thereof, the "Loan Documents");

         IN WITNESS WHEREOF, the parties have executed this First Amendment to
Amended and Restated Continuing Guaranty Agreement effective as of the date set
forth above.

                                  GUARANTOR:


                                  Education Lending Group, Inc.


                                  By: /s/ Perry D. Moore
                                     -------------------

                                  Name:  Perry D. Moore
                                       ----------------
                                  Title: SVP - Finance
                                        --------------


                                  Accepted this 6th day of June, 2003


                                  BENEFICIARY:


                                  FIFTH THIRD BANK


                                  By: /s/ Andrew K. Hauck
                                     --------------------
                                  Name: Andrew K. Hauck
                                       ----------------
                                  Title: Senior Vice President
                                        ----------------------


                                       2