Exhibit 24.12

                              POWER OF ATTORNEY


KNOW ALL MEN BY THESE PRESENTS:

      WHEREAS, AT&T CORP., a New York corporation (hereinafter referred to as
the "Company"), proposes to file with the Securities and Exchange Commission
(the "Commission"), under the provisions of the Securities Act of 1933, as
amended (the "Act"), a registration statement or registration statements with
respect to up to 60 million shares of AT&T Wireless Group Common Stock to be
offered under the various Company 401(k) Savings Plans including, without
limitation, AT&T Long Term Savings Plan for Management Employees, AT&T Long Term
Savings and Security Plan, AT&T Retirement Savings and Profit Sharing Plan, AT&T
of Puerto Rico, Inc. Long Term Savings and Security Plan, AT&T of Puerto Rico,
Inc. Long Term Savings Plan for Management Employees, AT&T Long Term Savings
Plan, AT&T Long Term Savings Plan - San Francisco, AT&T Wireless Services 401(k)
Retirement Plan, GRC International Employees' Deferred Income Plan and MediaOne
Group 401(k) Savings Plan; and

      WHEREAS, the Company proposes to file amendments with the Commission under
the Act to existing registration statements with respect to AT&T Common Stock
and Liberty Media Group Class A Common Stock to add additional Company 401(k)
Savings Plans to such registration statements including, without limitation,
AT&T Long Term Savings Plan - San Francisco, AT&T Wireless Services 401(k)
Retirement Plan, GRC International Employees' Deferred Income Plan and MediaOne
Group 401(k) Savings Plan; and

      WHEREAS, the Company, proposes to file with Commission, under the
provisions of the Act, a registration statement or statements with respect to up
to an additional 30 million shares of AT&T Common Stock to be offered under the
Company's 1997 Long Term Incentive Plan, as amended; and

      WHEREAS, the undersigned is a director of the Company, as indicated below
his signature:

      NOW, THEREFORE, the undersigned hereby constitutes and appoints C. H.
NOSKI, M. J. WASSER and E. M. DWYER, and each of them, as attorneys for him and
in his name, place and stead, and in his capacity as an officer of the Company,
to execute and file any such registration statements and amendments to existing
registration statements with respect to the above-described common shares, and
thereafter to execute and file any amended registration statement or statements
with respect thereto or amendments or supplements to any of the foregoing,
hereby giving and granting to said attorneys, and each of them, full power and
authority to do and perform each and every act and thing whatsoever requisite
and necessary to be done in and about the premises, as fully, to all intents and
purposes, as he might or could do if personally present at the doing thereof,
hereby ratifying and confirming all that said attorneys may or shall lawfully
do, or cause to be done, by virtue hereof.




      IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney
this 21st day of June, 2000.




                                            /s/ John C. Malone
                                            -----------------------------
                                            John C. Malone
                                            Director