Pursuant  to  Rule  425  under  the
                                             Securities  Act of 1933 and  deemed
                                             filed pursuant to Rule 14a-12 under
                                             the Securities Exchange Act of 1934


April 28, 2000


Dear Stockholder:

         We will hold our May 16, 2000 annual stockholders meeting as scheduled.
As you may know, on April 20, 2000, NBT Bancorp Inc. announced an agreement with
BSB Bancorp,  Inc. of Binghamton,  New York, under which BSB and NBT will merge.
In view of this significant transaction, we have determined that the vote by our
stockholders  at our annual  meeting  regarding  the  merger of NBT and  Pioneer
American Holding Company Corp. must be postponed to a later date.  Nevertheless,
we will convene our annual meeting on May 16, 2000 at 2:00 PM at the Holiday Inn
Arena in  Binghamton as we indicated in the proxy  materials  that we previously
mailed to you.

         We mailed you the proxy  statement  regarding  our May 16 meeting on or
about  April 5,  2000.  In the  event  you no  longer  have a copy of the  proxy
material and would like an  additional  copy,  please  contact our  Shareholders
Relations Office at 607-337-6216.

     At the May 16 meeting,  we will  request our  stockholders  to consider and
vote upon

         o        the election of the nominated directors,  including fixing the
                  number of directors at twelve;

         o        ratification  of the  Board's  selection  of  the  independent
                  auditor for the current year; and

         o        approval of the NBT Employee Stock Purchase Plan.

         Following consideration of these matters, we plan to entertain a motion
to adjourn  the May 16 meeting  and to  reconvene  the  meeting on a later date,
tentatively June 20, 2000 at 2:00 PM at the Holiday Inn Arena in Binghamton,  to
consider and vote upon the proposed merger between NBT and Pioneer American.

         The plan to adjourn the May 16 meeting and reconvene it on a later date
will  allow  us the time  necessary  for  preparation  of,  distribution  to and
consideration by our stockholders of supplemental  proxy information  related to
the Pioneer  American  merger which is required by the  Securities  and Exchange
Commission due to the BSB development. We appreciate your patience as we work to
provide you with  information in compliance with the laws and  regulations  that
govern these matters.


                                   Sincerely,


                                  /s/ Daryl R. Forsythe
                                  ---------------------
                                  Daryl R. Forsythe
                                  President and
                                  Chief Executive Officer








         This letter may be deemed to be solicitation material in respect of the
proposed  acquisition  of  Pioneer  American  by NBT  through  the  merger  of a
wholly-owned  subsidiary of NBT with Pioneer American,  pursuant to an Agreement
and Plan of  Merger,  dated as of  December  7, 1999 and  amended as of March 7,
2000, by and among NBT, a wholly-owned  subsidiary of NBT, and Pioneer  American
(the  "Agreement").  Filing of this  letter  is being  made in  connection  with
Regulation of Takeovers and Security Holder Communications (Release No. 33-7760,
34-42055) promulgated by the Securities and Exchange Commission ("SEC").

         NBT and its  directors  and  executive  officers  may be  deemed  to be
participants  in the  solicitation  of proxies  in  respect of the  transactions
contemplated by the Agreement.  These directors and executive  officers  include
the following: Daryl R. Forsythe, Michael J. Chewens, Martin A. Dietrich, Joe C.
Minor, John D. Roberts,  Everett A. Gilmour, J. Peter Chaplin, Peter B. Gregory,
William C. Gumble,  Bruce D. Howe,  Andrew S.  Kowalczyk,  Jr., Dan B. Marshman,
John G. Martines, John C. Mitchell, William L. Owens and Paul O. Stillman. As of
February 29, 2000, these directors and executive officers  beneficially owned in
the aggregate  1,415,558  shares,  or approximately  7.82%, of NBT's outstanding
common stock.

         In connection  with the proposed  merger,  NBT has filed a registration
statement  on SEC  Form S-4 with the  SEC,  File No.  333-30988,  which  the SEC
declared  effective on April 3, 2000. NBT and Pioneer American have prepared and
mailed to their  respective  stockholders  a joint  proxy  statement/prospectus,
dated April 3, 2000 (the "Proxy Statement/Prospectus"). NBT and Pioneer American
will  prepare  and  file  with  the  SEC  a  post-effective   amendment  to  the
aforementioned S-4 registration statement,  which will include a supplement (the
"Supplement")  to  the  Proxy  Statement/Prospectus.  Stockholders  of  NBT  are
encouraged to read the post-effective amendment and the Supplement because these
documents  will  contain  important  information  about  the  merger.  After the
post-effective  amendment is filed with the SEC, it will be available  for free,
both on the SEC's web site  (www.sec.gov) and from NBT's corporate  secretary.
The Form S-4 registration statement and the Proxy  Statement/Prospectus can also
be obtained at no cost in the same manner.

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