CORPORATE OFFICE 30 North LaSalle Street Suite 4000 Chicago, Illinois 60602-2507 Office: 312-630-1900 FAX: 312-630-1908 312-630-9299 TELEPHONE AND [LOGO] DATA SYSTEMS, INC. _____________________________________________________________________ January 13, 1998 American Paging, Inc. 1300 Godward Street NE #3100 Minneapolis, MN 55413 RE: Revolving Credit Agreement dated January 1, 1994, as amended (the "Revolving Credit Agreement"), between American Paging, Inc. ("API") and Telephone and Data Systems, Inc. ("TDS") Ladies and Gentlemen: This letter will constitute TDS's agreement to amend the Revolving Credit Agreement by changing all of the references to "$180,000,000" in the Revolving Credit Agreement to "$185,000,000." All of the other terms and conditions of the Revolving Credit Agreement shall remain in full force and effect. The amendment is subject to completion of American Paging's business plan and budget for 1998 and approval of an extension of credit from TDS to American Paging by the TDS Board of Directors. Please acknowledge your agreement to this amendment by executing the copy of this letter and return it to the undersigned. Very truly yours, TELEPHONE AND DATA SYSTEMS, INC. TELEPHONE AND DATA SYSTEMS, INC. By: /s/ LEROY T. CARLSON, JR. By: /s/ MURRAY L. SWANSON ------------------------- -------------------------- LeRoy T. Carlson, Jr. Murray L. Swanson President Executive Vice President, Finance Accepted and agreed to as of the date set forth above. AMERICAN PAGING, INC. By: /s/ TERRENCE T. SULLIVAN ------------------------------------ Terrence T. Sullivan President and Chief Executive Officer