Exhibit 99
November 27, 2000
This will confirm the agreement by and among all of the
undersigned that the Schedule 13D filed on or about this date with respect to
the beneficial ownership of the undersigned of shares of the Class A Common
Stock of TeleCorp PCS, Inc. is being filed on behalf of each of the undersigned.
This agreement may be executed in two or more counterparts, each of which shall
be deemed an original, but all of which together shall constitute one and the
same instrument.
AT&T CORP.
By: /S/ STEVEN V. GARFINKEL
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Name: Steven V. Garfinkel
Title: Assistant Secretary
AT&T WIRELESS PCS, LLC
By: AT&T Wireless Services, Inc., its manager
By: /S/ WILLIAM HAGUE
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Name: William Hague
Title: Senior Vice President
AT&T WIRELESS SERVICES, INC.
By: /S/ WILLIAM HAGUE
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Name: William Hague
Title: Senior Vice President
