Exhibit 10.6



December 22, 2000

AT&T Wireless PCS, LLC
7277 164th Avenue, N.E.
Redmond, WA 98052

          Re:  Amendment No. 1 to Letter Agreement Dated November 13, 2000
               Regarding Sale of Subject Shares

Ladies and Gentlemen:

          Reference is made to that certain letter agreement, dated November 13,
2000 (the "Letter Agreement"), between AT&T Wireless PCS, LLC ("AT&T PCS"), and
Gerald T. Vento (the "Management Stockholder"), setting forth certain rights and
obligations with respect to the shares of Voting Preference Stock, par value
$0.01 per share, Class C Common Stock, par value $0.01 per share, and Class D
Common Stock, par value $0.01 per share, (collectively, the "Subject Stock") of
TeleCorp PCS, Inc. (the "Company") held by the Management Stockholders. Defined
terms used herein and not otherwise defined shall have the meanings assigned in
the Letter Agreement.

          1. Notwithstanding anything to the contrary contained in the Letter
Agreement or in any Notice delivered pursuant thereto, in the event AT&T
exercises its rights and option under Section 2 of the Letter Agreement to
purchase (or designate another party to purchase) Subject Shares, the purchase
price per share payable by AT&T PCS (or such designee) for any such Subject
Shares shall be equal to the lesser of (i) the purchase price per share set
forth in the notice, and (ii) the average closing price per share for the
Company's Class A Common Stock for the five (5) trading days ending two (2) days
prior to the date of execution of the Sale Offer. Section 13 of the Letter
Agreement is hereby deleted in its entirety and the Letter Agreement shall have
no expiration date.

          2. This letter shall be deemed to be an amendment to the Letter
Agreement. All references to the Letter Agreement in any other agreements or
documents shall on and after the date hereof be deemed to refer to the Letter
Agreement as amended hereby. Except as amended hereby, the Letter Agreement
shall remain in full force and effect and is hereby ratified, adopted and
confirmed in all respects.

          3. This letter may be executed in counterparts, each of which shall be
deemed an original, but all of which together shall constitute one and the same
instrument.

                                        1




          If you are in agreement with the terms of this letter, please sign two
copies in the space provided below and return it to the undersigned.

                                   Very truly yours,

                                   AT&T WIRELESS SERVICES, INC.


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

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

Agreed and accepted as of the date hereof:





-----------------------------------------
GERALD T. VENTO