EXHIBIT 2.1



                              TERMINATION AGREEMENT


                  THIS TERMINATION  AGREEMENT (this "Agreement") is entered into
as of October 4, 2000, by and between NBT Bancorp Inc., a Delaware  corporation,
("NBT") and BSB  Bancorp,  Inc.,  a Delaware  corporation  ("BSB")  (NBT and BSB
together referred to herein as the "Parties").

         WHEREAS, BSB and NBT entered into a Confidentiality Agreement, dated as
of March 16, 2000 (the "Confidentiality Agreement");

                  WHEREAS,  NBT and BSB entered  into an  Agreement  and Plan of
Merger,  dated as of April 19, 2000 and amended as of May 17, 2000 (the  "Merger
Agreement");

                  WHEREAS, in connection with the Merger Agreement,  BSB and NBT
entered into the BSB Bancorp, Inc. Stock Option Agreement, dated as of April 19,
2000 (the "BSB Stock Option Agreement");

                  WHEREAS, in connection with the Merger Agreement,  NBT and BSB
entered into the NBT Bancorp Inc. Stock Option Agreement,  dated as of April 19,
2000 (the "NBT Stock Option Agreement");

                  WHEREAS,   the  boards  of  directors  of  NBT  and  BSB  have
determined that the Merger Agreement and the transactions  contemplated  thereby
are no longer in the best interests of the Parties;

                  NOW,  THEREFORE,  in consideration of the foregoing and of the
mutual covenants and agreements  hereinafter set forth, the Parties hereby agree
as follows:

1.       Termination of Agreements.

         a)  Pursuant  to Section  7.01(a) of the Merger  Agreement,  the Merger
Agreement is hereby  terminated,  and forthwith  shall be void and of no further
force or  effect.  No  provision  of the Merger  Agreement  shall  survive  such
termination,  including,  without  limitation,  Sections 5.06, 5.07, 5.08, 5.11,
7.02 and Article VIII of the Merger Agreement,  notwithstanding any provision of
the Merger Agreement to the contrary.




         b) Each of the BSB Stock  Option  Agreement  and the NBT  Stock  Option
Agreement  is hereby  terminated,  and shall be void and of no further  force or
effect.


2.   Confidentiality Agreement.

     The Confidentiality Agreement shall remain in effect for 18 months from the
date of this Agreement.

3.   Employees.

     Except with the prior  written  consent of the other party,  no Party shall
knowingly  employ any person who is now employed by the other Party for a period
of 18 months from the date of this Agreement.

4.   Mutual Release.

     Except  for the  provisions  of  this  Agreement  and  the  Confidentiality
Agreement, BSB and its affiliates on the one hand, and NBT and its affiliates on
the other,  hereby  remise,  release  and  forever  discharge  the other and its
affiliates, directors, officers, employees, agents and representatives and their
heirs, executors, beneficiaries, administrators, successors and assigns from any
and all manner of action and actions,  cause and causes of action, suits, debts,
dues,   sums  of  money,   accounts,   contracts,   controversies,   agreements,
liabilities,  promises, damages, judgments, claims or demands of whatsoever kind
or nature, in law or in equity relating to any statements,  acts or omissions by
such  other  Party  and its  agents  (whether  actual or  apparent),  employees,
representatives  and affiliates,  whether in their individual or  representative
capacities,  which either BSB and NBT or their  respective  affiliates  may have
against the other for actions taken or events  occurring in connection  with the
negotiation,  execution and termination of the Merger  Agreement,  the BSB Stock
Option  Agreement  and the  NBT  Stock  Option  Agreement  and the  transactions
contemplated thereby.

5.   Representations   and   Warranties  of  the  Parties.  Each of  BSB and NBT
hereby makes the following  representations  and  warranties to the other Party,
each of which is being  relied upon by the other Party as a material  inducement
to enter into and perform this Agreement:

     a) The execution,  delivery and performance of this Agreement has been duly
authorized by all necessary corporate action of such Party; and

     b) This Agreement has been duly and validly  executed and delivered by such
Party and it  constitutes  the  valid  and  binding  obligation  of such  Party,
enforceable in accordance  with its terms,  except as enforcement may be limited
by general  principles of equity whether applied in a court of law or a court of
equity and




by  bankruptcy,  insolvency  and similar laws  affecting  creditors'  rights and
remedies generally.

6.  Mutual Non-Disparagement.

     a) BSB.  Subsequent  to entering into this  Agreement,  each of BSB and its
affiliates shall not make to any regulator,  customer,  supplier, or employee of
NBT or its affiliates,  or to NBT  stockholders,  or to the general public,  any
statement  that  disparages  NBT or its  affiliates  or any of their  respective
officers,  directors,  shareholders,  employees and  affiliates,  except if such
statement is required by law or legal process.

     b) NBT.  Subsequent  to entering into this  Agreement,  each of NBT and its
affiliates shall not make to any regulator,  customer,  supplier, or employee of
BSB or its affiliates,  or to BSB  stockholders,  or to the general public,  any
statement  that  disparages  BSB or its  affiliates  or any of their  respective
officers,  directors,  shareholders,  employees and  affiliates,  except if such
statement is required by law or legal process.

7.   Expenses.

     The Parties will share  equally the expenses  listed on Schedule A attached
hereto.

8.   Press Releases; Regulatory Contacts.

     Promptly  following the execution of this Agreement,  NBT and BSB each will
issue a press release announcing the termination of the Merger Agreement and the
transactions  contemplated  thereby,  provided  that  each  Party  will have the
opportunity to review the other Party's press release prior to issuance.

     Legal  counsel  for NBT and BSB jointly  will  contact  the  Department  of
Justice  and the  Office of the  Comptroller  of the  Currency  to inform  these
agencies of the termination of the Merger  Agreement.  Furthermore,  NBT and BSB
shall  cooperate  with each other and take the necessary  steps to terminate the
agreement  reached with the Department of Justice on August 15, 2000 with regard
to the divestiture of BSB's Norwich branch office.

9.   Miscellaneous.

     a) This Agreement constitutes the entire agreement between the Parties with
respect  to the  subject  matter  hereof,  and it  supersedes  all prior oral or
written agreements, commitments, or understandings with respect to such matters;
and




     b) This Agreement may be signed in counterparts, none of which need contain
the  signature  of all the  Parties  and each of which  shall be deemed to be an
original.

     c) This Agreement  shall be governed by, and construed in accordance  with,
the laws of the State of Delaware,  regardless of the laws that might  otherwise
govern under applicable principles of conflicts of law.


                                     * * * *

                            [Signature page follows]






                  IN WITNESS WHEREOF, the Parties have executed this Termination
Agreement as of the date first above written.


                                   BSB BANCORP, INC.


                                   By:      /s/ Thomas L. Thorn
                                       -----------------------------------------
                                   Name: Thomas L. Thorn
                                   Title:   Acting President and Chief Executive
                                             Officer


                                   NBT BANCORP INC.


                                   By:      /s/ Daryl R. Forsythe
                                       -----------------------------------------
                                   Name:  Daryl R. Forsythe
                                   Title:  President and Chief Executive
                                               Officer