Form 12b-25
                    [As last amended in Release No. 34-31905,
                         February 23, 1993, F.R. 14628.]

                     U.S. SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                   FORM 12b-25
                           NOTIFICATION OF LATE FILING

                                  (Check One):
           [ ] 10-K [ ] 20-F [X] 11-K [ ] 10-Q [ ] Form N-SAR
           For  Period  Ended  December 31, 1999
           [ ] Transition  Report on Form 10-K
           [ ] Transition  Report on Form 20-F
           [ ] Transition Report on Form 11-K
           [ ] Transition Report  on  Form  10-Q
           [ ] Transition  Report  on  Form  N-SAR
           For Transition Period Ended:

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Read Attached Instruction Sheet Before Preparing Form.  Please Print or Type.

Nothing  in this  form  shall be  construed  to imply  that the  Commission  has
verified any information contained herein.

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If the notification  related to a portion of the filing checked above,  identify
the Item(s) to which the notification relates:

AT&T Long Term Savings Plan

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Part I - Registrant Information

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Full Name of Registration: AT&T Corp.
Former Name if Applicable: NA

Address of Principal Executive Office:
32 Avenue of the Americas, New York, New York  10013-2412
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Part II - Rules 12b-25 (b) and (c)

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If the subject report could not be filed without  unreasonable effort or expense
and the registrant seeks relief pursuant to Rule 12b-25(b), the following should
be completed. (Check box if appropriate)

     (a) The  reasons  describe  in  reasonable  detail in Part III of this form
could not be eliminated without unreasonable effort or expense;



     (b) The subject annual report,  semi-annual  report,  transition  report on
Form 10-K, Form 20-F, 11-k or Form N-SAR, or portion thereof will be filed on or
before the  fifteenth  calendar day following  the  prescribed  due date; or the
subject  quarterly report or transition  report on Form 10-Q, or portion thereof
will be filed on or before the fifth  calendar day following the  prescribed due
date; and

     (c) The accountant's  statement or other exhibit required by Rule 12b-25(c)
has been attached if applicable.

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Part III - Narrative

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State below in reasonable  detail the reasons why Form 10-K,  20-F,  11-K, 10-Q,
N-SAR or the transition  report or portion thereof could not be filed within the
prescribed time period.

Independent  accountants  failed to complete  financial  information  within the
prescribed time.

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Part IV - Other Information

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     (1) Name  and  telephone  number of  person  to contact in  regard to  this
notification: Katherine Szafran, (908) 221-4369

     (2) Have all other periodic  reports  required under section 13 or 15(d) of
the Securities  Exchange Act of 1934 or section 20 of the Investment Company Act
of 1940  during the  preceding  12 months or for such  shorter  period  that the
registrant was required to file such report(s) been filed.  If the answer is no,
identify report(s).

                                                                 [X] Yes  [ ] No

     (3) Is it anticipated that any significant  change in results of operations
from the corresponding  period for the last fiscal year will be reflected by the
earnings statements to be included in the subject report or portion thereof?

                                                                 [ ] Yes  [X] No

     If so: attach an explanation of the anticipated  change,  both  narratively
and  quantitatively,  and, if  appropriate,  state the reasons why a  reasonable
estimate of the results cannot be made.


AT&T  Corp.  has  caused  this  notification  to be signed on its  behalf by the
undersigned thereunto duly authorized.

Date: June 28, 2000                /s/  John W. Thomson
                                   -------------------------
                                   By:  John W. Thomson