FORM 10-K/A

                       SECURITIES AND EXCHANGE COMMISSION

                              WASHINGTON, DC 20549

                             AMENDMENT No. 1 TO THE
                ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF
                       THE SECURITIES EXCHANGE ACT OF 1934

                   For The Fiscal Year Ended December 31, 1999


                          Commission File Number 1-1105

                                   AT&T CORP.

          A NEW YORK                                     I.R.S. EMPLOYER
          CORPORATION                                     NO. 13-4924710

            32 Avenue of the Americas, New York, New York 10013-2412
                          Telephone Number 212-387-5400

Securities  registered  pursuant  to  Section  12(b)  of the Act:  See  attached
SCHEDULE A.

Securities registered pursuant to Section 12(g) of the Act:  None.

Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the  preceding 12 months (or for such  shorter  period that the  registrant  was
required  to file  such  reports),  and  (2) has  been  subject  to such  filing
requirements for the past 90 days. Yes....x.... No........

Indicate by check mark if disclosure of delinquent  filers  pursuant to Item 405
of Regulation S-K is not con-tained  herein,  and will not be contained,  to the
best of registrant's  knowledge,  in definitive proxy or information  statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K. [ ]

At  December  31,  2000,  the  aggregate  market  value of voting  stock held by
non-affiliates   was   approximately   $108  billion.   At  December  31,  2000,
3,759,581,097  shares  shares of AT&T common stock,  361,814,400  shares of AT&T
Wireless Group  tracking  stock,  2,423,250,694  shares of Class A Liberty Media
Group  tracking  stock and  216,829,064  shares of Class B Liberty  Media  Group
tracking stock were outstanding.

DOCUMENTS INCORPORATED BY REFERENCE
(1) Portions of the  registrant's  annual  report to  shareholders  for the year
ended  December 31, 1999 (Part II) (2) Portions of the  registrant's  definitive
proxy  statement  dated  March 27,  2000  issued in  connection  with the annual
meeting of shareholders (Part III)

<PAGE>

                                   SCHEDULE A

           Securities registered pursuant to Section 12(b) of the Act:

                                                     Name of each exchange on
          Title of each class                            which registered

Common Shares                                 #      New York, Boston, Chicago,
   (Par Value $1 Per Share)                   ####   Philadelphia and Pacific
                                              #      Stock Exchanges
                                              #
                                              #
Class A Liberty Media Group Tracking          #
   Shares (common, Par Value $1 Per Share)    #
                                              ####   New York Stock Exchange
Class B Liberty Media Group Tracking          #
   Shares (common, Par Value $1 Per Share)    #
                                              #
                                              #
                                              #
Thirty-Five Year 5-1/8% Debentures, due       #
  April 1, 2001                               #
                                              #
Ten Year 7-1/8% Notes, due January 15, 2002   #
                                              #
Three Year 61/2% Notes due September 15, 2002 #
                                              #
Five Year 5 5/8% Notes due March 15, 2004     #
                                              #
Ten Year 6-3/4% Notes, due April 1, 2004      #
                                              #
Ten Year 7% Notes, due May 15, 2005           #
                                              #
Twelve Year 7-1/2% Notes, due June 1, 2006    ###### New York Stock Exchange
                                              #
Twelve Year 7-3/4% Notes, due March 1, 2007   #
                                              #
Ten Year 6% Notes due March 15, 2009          #
                                              #
Thirty Year 8-1/8% Debentures, due            #
  January 15, 2022                            #
                                              #
Thirty Year 8.35% Debentures, due             #
  January 15, 2025                            #
                                              #
Thirty-Two Year 8-1/8% Debentures, due        #
  July 15, 2024                               #
                                              #
Thirty Year 61/2% Notes due March 15, 2029    #
                                              #
Forty Year 8-5/8% Debentures, due             #
  December 1, 2031                            #

<PAGE>

The undersigned registrant hereby amends its Form 10-K filed with the Securities
Exchange  Commission for the year ended December 31, 1999 to file Exhibit 13 and
to file the Consent of PricewaterhouseCoopers, LLP.

                                     PART IV

Item 14.  Exhibits, Financial Statement Schedule, and Reports on Form 8-K.

      (a)  Documents filed as a part of the report:

      (1)  Financial Statements:
                                                            Pages

                                                            -----

              Report of Management .......................    *
              Report of Independent Accountants ..........    *


           Statements:

              Consolidated Statements of Income ..........    *
              Consolidated Balance Sheets ................    *
              Consolidated Statements of Changes in
                Shareowners' Equity ......................    *
              Consolidated Statements of Cash Flows ......    *
              Notes to Consolidated Financial Statements .    *

     ------------

*Incorporated  herein by reference to the appropriate  portions of the Company's
annual report to  shareholders  for the year ended December 31, 1999.  (See Part
II.)

(2)  Financial Statement Schedule:

              Report of Independent Accountants ..........   **

           Schedule:

              II -- Valuation and Qualifying Accounts ....   **

      ---------------

**Filed  with the  Company's  Annual  Report  on Form  10-K  for the year  ended
December 31, 1999 filed on March 27, 2000.

           Separate  financial  statements  of Liberty  Media Group,  which is a
           "significant  subsidiary"  pursuant to the  provisions  of Regulation
           S-X, Article 3-9, were included as Exhibit 99 to the Company's Annual
           Report on Form 10-K for the year  ended  December  31,  1999 filed on
           March 27, 2000.

      (3)  Exhibits:

 Exhibit Number:

 (13)             Specified  portions (pages 12 through 55  and  the inside back
                  cover) of the Company's  Annual Report to Shareholders for the
                  year ended December 31, 1999.

 (23)             Consent of PricewaterhouseCoopers, LLP

                  AT&T will  furnish,  without  charge,  to a  shareholder  upon
                  request a copy of the annual  report to  shareholders  and the
                  proxy statement,  portions of which are incorporated herein by
                  reference  thereto.  AT&T will  furnish  any other  exhibit at
                  cost.

<PAGE>

                                   SIGNATURES

         Pursuant to the  requirements  of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the registrant has duly caused this amendment to be signed
on its behalf by the undersigned, thereunto duly authorized.

                                   AT&T Corp.

                                  /s/   M. J. Wasser
                                  -------------------------
                                  By:   M. J. Wasser
                                        Vice President - Law and Secretary

January 25, 2001