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                              UNITED STATES
                   SECURITIES AND EXCHANGE COMMISSION
                         Washington, D.C. 20549
                                    
                                    
                              SCHEDULE 13G
                                    
                Under the Securities Exchange Act of 1934
                                    
                           (Amendment No. 2)*
                                    
                                    
                             AMBAC INC /DE/ 
                            (Name of Issuer)
                                    
                      Common Stock, $.01 Par Value
                     (Title of Class of Securities)
                                    
                                    
                                023139108
                             (CUSIP Number)
                                    

Check the following box if a fee is being paid with this
statement []. (A fee is not required only if the filing person:
(1) has a previous statement on file reporting beneficial
ownership of more than five percent of the class of securities
described in Item 1; and (2) has filed no amendment subsequent
thereto reporting beneficial ownership of five percent or less of
such class.) (See Rule 13d-7).

*The remainder of this cover page shall be filled out for a
reporting person's initial filing on this form with respect to
the subject class of securities, and for any subsequent amendment
containing information which would alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page
shall not be deemed to be "filed" for the purpose of Section 18
of the Securities Exchange Act of 1934 ("Act") or otherwise
subject to the liabilities of that section of the Act but shall
be subject to all other provisions of the Act (however, see the
Notes).

                            Page 1 of 5 pages


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Schedule 13G
CUSIP No. 023139108

1.  NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

    Harris Associates Investment Trust,
    Series Designated The Oakmark Fund         CIK 0000872323
    36-3764848

2.  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                        (a) [ ]
    N/A                                                 (b) [ ]


3.  SEC USE ONLY


4.  CITIZENSHIP OR PLACE OF ORGANIZATION

    Massachusetts

    NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON
    WITH --

            5.  SOLE VOTING POWER          None

            6.  SHARED VOTING POWER        2,194,900   

            7.  SOLE DISPOSITIVE POWER     None

            8.  SHARED DISPOSITIVE POWER   2,194,900   

9.  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    2,194,900   

10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN 
   SHARES*

    N/A

11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

    6.27%

12. TYPE OF REPORTING PERSON*

    IV

                            Page 2 of 5 pages


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Item 1(a)      Name of Issuer:

               AMBAC INC /DE/ 

Item 1(b)      Address of Issuer's Principal Executive Offices:

               One State Street Plaza
               New York, NY 10004         

Item 2(a)      Name of Person Filing:

               Harris Associates Investment Trust
               Series Designated The Oakmark Fund

Item 2(b)      Address of Principal Business Office:

               Two North LaSalle Street, Suite 500
               Chicago, Illinois 60602-3790

Item 2(c)      Citizenship:

               The filing person is a Massachusetts Business
               trust.

Item 2(d)      Title of Class of Securities:

               Common Stock, $.01 Par Value

Item 2(e)      CUSIP Number:

               023139108

Item 3         Type of Person:

                    (d)  Investment company registered under
                         section 8 of the  
                         Investment Company Act

Item 4         Ownership (at December 31, 1996):

                    (a)  Amount owned "beneficially" within the
                         meaning of rule 13d-3:

                         2,194,900   

                    (b)  Percent of class:
                         
                         6.27%

                                 Page 3 of 5 pages
     

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                    (c)  Number of shares as to which such person
                         has:

                        (i)     sole power to vote or to direct   
                                the vote: None
                        (ii)    shared power to vote or to direct 
                                the vote: 2,194,900   
                        (iii)   sole power to dispose or to       
                                direct the disposition of:  None
                        (iv)    shared power to dispose or to     
                                direct the disposition of:        
                                2,194,900   

Item 5        Ownership of Five Percent or Less of a Class:

              N/A

Item 6        Ownership of More than Five Percent on Behalf of    
              Another Person:
                         
              N/A
 
Item 7        Identification and Classification of the Subsidiary 
             Which Acquired the Security Being Reported on by     
             the Parent Holding Company:

              N/A

Item 8        Identification and Classification of Members of the 
              Group:

              N/A

Item 9        Notice of Dissolution of Group:

              N/A
                                         
Item 10        Certification:

               By signing below I certify that, to the best of my
               knowledge and belief, the securities referred to
               above were acquired in the ordinary course of
               business and were not acquired for the purpose of
               and do not have the effect of changing or
               influencing the control of the issuer of such
               securities and were not acquired in connection
               with or as a participant in any transaction having
               such purpose or effect.

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                                  Signature


After reasonable inquiry and to the best of my knowledge and
belief, I certify that the information set forth in this
statement is true, complete and correct.

Dated:   February 3, 1997 

                                   Harris Associates Investment   
                                   Trust, Series Designated The   
                                   Oakmark Fund


                                   By:/s/Anita M. Nagler          
                                      Anita M. Nagler
                                      Secretary

                                   Page 5 of 5 Pages


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