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                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                     FORM 15

CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF
THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER
SECTIONS 13 AND 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934.

                                   Commission File Number        0-20809        
                                                          ----------------------

                                SIS Bancorp, Inc.
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             (Exact name of registrant as specified in its charter)


               1441 Main Street, Springfield, Massachusetts 01102
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   (Address, including zip code, and telephone number, including area code,
                  of registrant's principal executive offices)


                     Common Stock, par value $.01 per share
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            (Title of each class of securities covered by this Form)


                                       N/A
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         (Titles of all other classes of securities for which a duty to
               file reports under section 13(a) or 15(d) remains)

     Please place an X in the box(es) to designate the appropriate rule
provision(s) relied upon to terminate or suspend the duty to file reports:



    Rule 12g-4(a)(1)(i)      [X]            Rule 12h-3(b)(1)(i)      [ ]

    Rule 12g-4(a)(1)(ii)     [ ]            Rule 12h-3(b)(1)(ii)     [ ]

    Rule 12g-4(a)(2)(i)      [ ]            Rule 12h-3(b)(2)(i)      [ ]

    Rule 12g-4(a)(2)(ii)     [ ]            Rule 12h-3(b)(2)(ii)     [ ]

                                            Rule 15d-6               [ ]


     Approximate number of holders of record as of the certification or notice
date:      0
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     Pursuant to the requirements of the Securities Exchange Act of 1934,
Peoples Heritage Financial Group, Inc., as successor to SIS Bancorp, Inc., has
caused this certification/notice to be signed on its behalf by the undersigned
duly authorized person.

Date:    January 4, 1999              By:/s/ Peter J. Verrill                 
     ------------------------            -------------------------------------
                                         Peter J. Verrill, Executive Vice
                                         President, Chief Financial
                                         Officer and Treasurer

Instruction: This form is required by Rules 12g-4, 12h-3 and 15d-6 of the
General Rules and Regulations under the Securities Exchange Act of 1934. The
registrant shall file with the Commission three copies of Form 15, one of which
shall be manually signed. It may be signed by an officer of the registrant, by
counsel or by any other duly authorized person. The name and title of the person
signing the form shall be typed or printed under the signature.