SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                   FORM 8-K/A

                                 CURRENT REPORT
                     PURSUANT TO SECTION 13 OR 15(D) OF THE

                         SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported)       July  1, 2000
                                                  ----------------------

                                NBT Bancorp Inc.
- ------------------------------------------------------------------------
               (Exact Name of Registrant as Specified in Charter)


         Delaware                   0-14703            16-1268674
- ------------------------------------------------------------------------
   (State or Other Jurisdiction   (Commission         (IRS Employer
         of Incorporation)        File Number)   Identification Number)


   52 South Broad Street, Norwich, New York               13815
- ------------------------------------------------------------------------
(Address of Principal Executive Office)                 (Zip Code)

Registrant's telephone number, including area code     607/337-2265
                                                   ---------------------
                                       N/A
- ------------------------------------------------------------------------
          (Former Name or Former Address, if Changed Since Last Report)



Item 7.  Financial Statements, Pro Forma Financial Information and Exhibits.

         (a) The (i) consolidated  audited balance sheets of Pioneer American as
of December  31, 1999 and 1998 and (ii)  consolidated  statements  of income and
cash flows of Pioneer  American  for the fiscal  years ended  December 31, 1999,
1998 and 1997 have been filed with the SEC as part of Pioneer  American's Annual
Report  on  Form  10-K,  filed  March  13,  2000  (File  No.  0-14506),  and are
incorporated  by reference.  The (iii) unaudited  consolidated  balance sheet of
Pioneer American as of March 31, 2000 and (iv) unaudited consolidated statements
of income and cash flows of Pioneer  American  for the three  months ended March
31,  2000 and 1999 have been filed  with the SEC as part of  Pioneer  American's
Quarterly Report on Form 10-Q,  filed May 10, 2000 (File No.  0-14506),  and are
incorporated herein by reference.

         The (i) consolidated audited balance sheets of BSB Bancorp,  Inc. as of
December 31, 1999 and 1998 and (ii)  consolidated  statements of income and cash
flows of BSB Bancorp for the fiscal years ended December 31, 1999, 1998 and 1997
have been  filed  with the SEC as part of BSB  Bancorp's  Annual  Report on Form
10-K,  filed  March  30,  2000  (File  No.  0-17177),  and are  incorporated  by
reference.  The (iii) unaudited  consolidated balance sheet of BSB Bancorp as of
March 31, 2000 and (iv)  unaudited  consolidated  statements  of income and cash
flows of BSB  Bancorp  for the three  months  ended March 31, 2000 and 1999 have
been filed with the SEC as part of BSB Bancorp's  Quarterly Report on Form 10-Q,
filed May 15, 2000 (File No. 0-17177), and are incorporated herein by reference.

         (b)  Pro  Forma  Financial  Information.  The (i)  pro  forma  combined
condensed  statements of income of NBT, Pioneer American and BSB Bancorp for the
three  months  ended March 31, 2000 and 1999,  and the years ended  December 31,
1999, 1998 and 1997; and (ii) pro forma combined condensed balance sheet of NBT,
Pioneer American and BSB Bancorp as of March 31, 2000.

         (c) Exhibits.


         The  following   exhibits  are  filed  with  this  Current   Report  or
incorporated by reference into this Current Report on Form 8-K:

Exhibit
Number            Description
- ------            -----------

23.1              Consent of KPMG LLP

23.2              Consent of PricewaterhouseCoopers LLP




99.1              Consolidated  audited balance sheets of Pioneer American as of
                  December  31,  1999 and 1998 and  consolidated  statements  of
                  income and cash flows of Pioneer American for the fiscal years
                  ended  December  31,  1999,  1998  and 1997  (incorporated  by
                  reference to Pioneer  American's  Annual  Report on Form 10-K,
                  filed March 13, 2000, File No. 0-14506).

99.2              Unaudited consolidated balance sheet of Pioneer American as of
                  March 31, 2000 and unaudited consolidated statements of income
                  and cash flows of Pioneer  American for the three months ended
                  March 31, 2000 and 1999  (incorporated by reference to Pioneer
                  American's  Quarterly Report on Form 10-Q, filed May 10, 2000,
                  File No. 0- 14506).

99.3              Consolidated  audited  balance  sheets  of BSB  Bancorp  as of
                  December  31,  1999 and 1998 and  consolidated  statements  of
                  income and cash  flows of BSB  Bancorp  for the  fiscal  years
                  ended  December  31,  1999,  1998  and 1997  (incorporated  by
                  reference to BSB Bancorp's  Annual Report on Form 10-K,  filed
                  March 30, 2000, File No. 0- 17177).

99.4              Unaudited  consolidated  balance  sheet of BSB  Bancorp  as of
                  March 31, 2000 and unaudited consolidated statements of income
                  and cash flows of BSB Bancorp for the three months ended March
                  31, 2000 and 1999  (incorporated by reference to BSB Bancorp's
                  Quarterly  Report on Form 10-Q,  filed May 15, 2000,  File No.
                  0-17177).


           UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL STATEMENTS

The following  unaudited pro forma condensed combined balance sheet presents the
financial  position of NBT Bancorp Inc. (NBT),  Pioneer American Holding Company
Corp  (Pioneer  American),  and BSB  Bancorp,  Inc.  (BSB) as of March 31,  2000
assuming that both mergers had occurred as of March 31, 2000 after giving effect
to certain  pro forma  adjustments  described  in the  accompanying  notes.  The
following  unaudited pro forma condensed  combined  statements of income for the
three  months  ended March 31, 2000 and 1999,  and the years ended  December 31,
1999,  1998, and 1997 present the combined  historical  results of operations of
NBT,  Pioneer  American,  and BSB as if the mergers had been completed as of the
first day of the period presented.  The historical financial  information of NBT
has been  restated to include the effects of the merger with Lake Ariel  Bancop,
Inc.  (Lake  Ariel),  which was  completed  on  February  17,  2000 and has been
accounted for as a pooling of interests.  Pro forma earnings per share are based
on the  exchange  ratios  of  1.805  and 2.0 for the  Pioneer  American  and BSB
mergers,  respectively.  The fiscal years of NBT, Pioneer American,  and BSB end
December 31. The unaudited pro forma condensed  combined  balance sheet reflects
estimated  non-recurring  charges  that may be incurred in  connection  with the
mergers.

The unaudited pro forma condensed  combined  financial  statements were prepared
giving  effect to the mergers on the  pooling of  interests  accounting  method.
Under this method of accounting, the recorded assets, liabilities, stockholders'
equity,  income and expense of NBT, Pioneer  American,  and BSB are combined and
reflected  at their  historical  amounts,  except  as noted in the  accompanying
notes.

The combined  company  expects to achieve certain merger benefits in the form of
operating expense reductions and revenue  enhancements.  The unaudited pro forma
condensed  combined  statements  of income do not  reflect  potential  operating
expense reductions or revenue  enhancements that are expected to result from the
mergers,  and  therefore  may  not  be  indicative  of  the  results  of  future
operations.  No assurance  can be given with  respect to the  ultimate  level of
operating expense reductions or revenue enhancements.

The unaudited pro forma condensed combined  financial  statements should be read
in  conjunction  with,  and are qualified in their  entirety by, the  historical
consolidated  financial  statements  and  accompanying  notes  of  NBT,  Pioneer
American,  and BSB and the supplemental  consolidated  financial  statements and
accompanying  notes of NBT,  which have been  restated to include the effects of
the Lake Ariel merger. These supplemental  financial statements were included in
Current  Report on Form 8-K,  dated March 31,  2000 and filed with the SEC.  The
following historical financial  information of Pioneer American and BSB has been
derived from the respective companies' interim consolidated financial statements
as of March 31,  2000 and for the three  months  ended  March 31,  2000 and 1999
which are included in the  respective  companies  Form 10-Q for the three months
ended  March  31,  2000 and are  incorporated  by  reference  herein,  and their
respective  consolidated  financial  statements  and  accompanying  notes  as of
December  31,  1999 and 1998 and for each of the years in the three year  period
ended December 31, 1999,  which were included in the respective  companies' Form
10-K for the year ended December 31, 1999 and incorporated by reference  herein.
The unaudited pro forma condensed  combined  financial  statements are presented
for informational purposes only. These statements are not necessarily indicative
of the combined  financial  position and results of  operations  that would have
occurred if the mergers had been completed on March 31, 2000 or at the beginning
of the respective periods presented or that may be attained in the future.



Unaudited Pro Forma Condensed Combined Balance Sheet
March 31, 2000
(in thousands)




                                                                                        Pioneer American
                                                                         NBT                Holding             Pro Forma
                                                                    Bancorp Inc.         Company Corp.         Adjustments
                                                                    ------------         -------------         -----------
                                                                                                      
ASSETS
Cash and cash equivalents                                             $ 60,823              $ 13,216               --
Securities available for sale, at fair value                           497,528               105,239               --
Securities held to maturity (fair value-NBT Bancorp Inc.
  $75,808, BSB Bancorp, Inc. $13,208, and Pioneer
   American Holding Company Corp. $34,560)                              78,772                35,746               --
Loans                                                                1,295,651               245,147
Less:   Allowance for loan losses                                       17,543                 3,145               --
- -------------------------------------------------------------------------------------------------------------------------------
   Net loans                                                         1,278,108               242,002               --
Premises and equipment, net                                             40,292                 5,910               --
Other assets                                                            73,583                13,615            1,300
- -------------------------------------------------------------------------------------------------------------------------------
TOTAL ASSETS                                                       $ 2,029,106             $ 415,728          $ 1,300
===============================================================================================================================



                                                                  NBT
                                                            Pioneer American
                                                                Combined               BSB             Pro Forma       Combined
                                                               Pro Forma          Bancorp, Inc.       Adjustments      Pro Forma
                                                               ---------          -------------       -----------      ---------
                                                                                                         
ASSETS
Cash and cash equivalents                                   $ 74,039 16          $ 47,718 16         $    --         $ 121,757
Securities available for sale, at fair value                    602,767              382,703              --           985,470
Securities held to maturity (fair value-NBT Bancorp Inc.
  $75,808, BSB Bancorp, Inc. $13,208, and Pioneer
   American Holding Company Corp. $34,560)                      114,518               13,079              --           127,597
Loans                                                         1,540,798            1,745,959                         3,286,757
Less:   Allowance for loan losses                                20,688               31,705              --            52,393
- -----------------------------------------------------------------------------------------------------------------------------------
   Net loans                                                  1,520,110            1,714,254              --         3,234,364
Premises and equipment, net                                      46,202               15,541              --            61,743
Other assets                                                     88,498               57,569           4,500           150,567
- -----------------------------------------------------------------------------------------------------------------------------------
TOTAL ASSETS                                                $ 2,446,134          $ 2,230,864         $ 4,500       $ 4,681,498
===================================================================================================================================







                                                                                        Pioneer American
                                                                         NBT                Holding             Pro Forma
                                                                    Bancorp Inc.         Company Corp.         Adjustments
                                                                    ------------         -------------         -----------

LIABILITIES AND STOCKHOLDERS' EQUITY
Deposits:
 Demand (noninterest bearing)                                         $ 210,579             $ 45,842              $ --
 Savings,NOW, and money market                                          490,328              110,880                --
 Time                                                                   822,842              143,152                --
- -------------------------------------------------------------------------------------------------------------------------------
  Total deposits                                                      1,523,749              299,874                --
Borrowings                                                              327,238               79,489                --
Other liabilities                                                        15,587                4,272             5,100
Mandatorily redeemable preferred securities of subsidiary                                         --                --
- -------------------------------------------------------------------------------------------------------------------------------
  Total liabilities                                                   1,866,574              383,635             5,100
- -------------------------------------------------------------------------------------------------------------------------------


                                                                  NBT
                                                            Pioneer American
                                                                Combined               BSB             Pro Forma       Combined
                                                               Pro Forma          Bancorp, Inc.       Adjustments      Pro Forma
                                                               ---------          -------------       -----------      ---------
                                                                                                         

LIABILITIES AND STOCKHOLDERS' EQUITY
Deposits:
 Demand (noninterest bearing)                                  $ 256,421              $ 139,639        $    --          396,060
 Savings,NOW, and money market                                   601,208                653,091             --        1,254,299
 Time                                                            965,994              1,106,548             --        2,072,542
- ---------------------------------------------------------------------------------------------------------------------------------
  Total deposits                                               1,823,623              1,899,278             --        3,722,901
Borrowings                                                       406,727                135,982             --          542,709
Other liabilities                                                 24,959                  8,588         16,500           50,047
Mandatorily redeemable preferred securities of subsidiary             --                 30,000             --           30,000
- ---------------------------------------------------------------------------------------------------------------------------------
  Total liabilities                                            2,255,309              2,073,848         16,500        4,345,657
- ---------------------------------------------------------------------------------------------------------------------------------






                                                                                        Pioneer American
                                                                         NBT                Holding             Pro Forma
                                                                    Bancorp Inc.         Company Corp.         Adjustments
                                                                    ------------         -------------         -----------
                                                                                                      
Stockholders' equity:
  Preferred stock                                                          --                 --                      --
  Common stock                                                            186              2,935                  (2,883)
  Additional paid-in-capital                                          167,047             11,962                   1,153
  Retained earnings                                                    24,225             22,355                  (3,800)
  Accumulated other comprehensive income (loss)                       (17,615)            (3,429)                     --
  Common stock in treasury, at cost                                   (11,311)            (1,730)                  1,730
- ------------------------------------------------------------------------------------------------------------------------------------
  Total stockholders' equity                                          162,532             32,093                  (3,800)
- ------------------------------------------------------------------------------------------------------------------------------------
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY                        $ 2,029,106          $ 415,728                 $ 1,300
====================================================================================================================================


                                                                        NBT
                                                                  Pioneer American
                                                                      Combined               BSB             Pro Forma     Combined
                                                                     Pro Forma          Bancorp, Inc.       Adjustments    Pro Forma
                                                                     ---------          -------------       -----------    ---------
                                                                                                         
Stockholders' equity:
  Preferred stock                                                          --                 --              --                 --
  Common stock                                                            238                114              91                443
  Additional paid-in-capital                                          180,162             37,590         (13,548)           204,204
  Retained earnings                                                    42,780            143,481         (12,000)           174,261
  Accumulated other comprehensive income (loss)                       (21,044)           (10,712)             --            (31,756)
  Common stock in treasury, at cost                                   (11,311)           (13,457)         13,457            (11,311)
- ------------------------------------------------------------------------------------------------------------------------------------
  Total stockholders' equity                                          190,825            157,016         (12,000)           335,841
- ------------------------------------------------------------------------------------------------------------------------------------
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY                        $ 2,446,134        $ 2,230,864        $  4,500        $ 4,681,498
====================================================================================================================================

See accompanying notes to unaudited pro forma condensed combined financial statements





Unaudited Pro Forma Condensed Combined Statement of Income
For the Three Months Ended March 31, 2000



                                                                                            Pioneer
                                                                                           American                       NBT
                                                                                             Holding               Pioneer American
                                                                              NBT            Company    Pro Forma      Combined
                                                                          Bancorp Inc.         Corp.    Adjustments     Pro Forma
                                                                          ------------         -----    -----------     ---------
                                                                                                              
Interest and fee income:
 Loan                                                                         $27,189        $5,048     $       --        $32,237
 Securities                                                                     9,865         2,358             --         12,223
 Other                                                                            402             4             --            406
 --------------------------------------------------------------------------------------------------------------------------------
   Total interest and fee income:                                              37,456         7,410             --         44,866
 --------------------------------------------------------------------------------------------------------------------------------

Interest expense:
 Deposits                                                                      13,446         2,637             --         16,083
 Borrowings                                                                     4,400         1,135             --          5,535
 --------------------------------------------------------------------------------------------------------------------------------
  Total interest expense                                                       17,846         3,772             --         21,618
 --------------------------------------------------------------------------------------------------------------------------------
 Net interest income                                                           19,610         3,638             --         23,248
 Provision for loan losses                                                      1,334           120             --          1,454
 --------------------------------------------------------------------------------------------------------------------------------
 Net interest income after provision for loan losses                           18,276         3,518             --         21,794
 --------------------------------------------------------------------------------------------------------------------------------

Noninterest income:
 Trust                                                                            860            --             --            860
 Service charges on deposit accounts                                            1,620           526             --          2,146
 Net security gains (losses)                                                       --            --             --             --
 Other                                                                          1,135           195             --          1,330
 --------------------------------------------------------------------------------------------------------------------------------
  Total noninterest income                                                      3,615           721             --          4,336
 --------------------------------------------------------------------------------------------------------------------------------


Noninterest expense:
  Salaries and employee benefits                                                7,081         1,322             --          8,403
  Office supplies and postage                                                     592           119             --            711
  Occupancy                                                                     1,232           269             --          1,501
  Equipment                                                                     1,137           225             --          1,362
  Professional fees and outside services                                          756           240             --            996
  Data processing and communications                                            1,132            96             --          1,228
  Amortization of intangible assets                                               312            10             --            322
  Merger and acquisition charges                                                1,122            --             --          1,122
  Other operating                                                               1,619           494             --          2,113
 --------------------------------------------------------------------------------------------------------------------------------
   Total noninterest expense                                                   14,983         2,775             --         17,758
 --------------------------------------------------------------------------------------------------------------------------------
 Income before income taxes                                                     6,908         1,464             --          8,372
 Income taxes                                                                   2,667           425             --          3,092
 --------------------------------------------------------------------------------------------------------------------------------

 --------------------------------------------------------------------------------------------------------------------------------
   Net Income                                                                 $ 4,241        $1,039     $       --        $ 5,280
 ================================================================================================================================

Weighted Average Shares Outstanding
  Basic                                                                        18,028         2,864                        23,198
  Diluted                                                                      18,134         2,887                        23,345

Earnings Per Share
  Basic                                                                          0.24          0.36                          0.23
  Diluted                                                                        0.23          0.36                          0.23


                                                                                                                          NBT
                                                                                                                          BSB
                                                                                                                        Pioneer
                                                                                         BSB          Pro Forma         Combined
                                                                                     Bancorp, Inc.    Adjustments       Pro Forma
                                                                                     -------------    -----------       ---------
                                                                                                          
Interest and fee income:
 Loan                                                                                 $39,593           $       --        $71,830
 Securities                                                                             6,674                   --         18,897
 Other                                                                                     13                   --            419
- ------------------------------------------------------------------------------------------------------------------------------------
Total interest and fee income:                                                         46,280                   --         91,146
- ------------------------------------------------------------------------------------------------------------------------------------
Interest expense:
 Deposits                                                                              21,319                   --         37,402
 Borrowings                                                                             2,582                   --          8,117
- ------------------------------------------------------------------------------------------------------------------------------------
  Total interest expense                                                               23,901                   --         45,519
- ------------------------------------------------------------------------------------------------------------------------------------
 Net interest income                                                                   22,379                   --         45,627
 Provision for loan losses                                                              4,608                   --          6,062
- ------------------------------------------------------------------------------------------------------------------------------------
 Net interest income after provision for loan losses                                   17,771                   --         39,565
- ------------------------------------------------------------------------------------------------------------------------------------
Noninterest income:
 Trust                                                                                    331                   --          1,191
 Service charges on deposit accounts                                                    1,213                   --          3,359
 Net security gains (losses)                                                               --                   --             --
 Other                                                                                  1,817                   --          3,147
 -----------------------------------------------------------------------------------------------------------------------------------
  Total noninterest income                                                              3,361                   --          7,697
 -----------------------------------------------------------------------------------------------------------------------------------


Noninterest expense:
  Salaries and employee benefits                                                        5,899                   --         14,302
  Office supplies and postage                                                             393                   --          1,104
  Occupancy                                                                               727                   --          2,228
  Equipment                                                                               442                   --          1,804
  Professional fees and outside services                                                1,479                   --          2,475
  Data processing and communications                                                      416                   --          1,644
  Amortization of intangible assets                                                        96                   --            418
  Merger and acquisition charges                                                           --                   --          1,122
  Other operating                                                                       2,261                   --          4,374
- ------------------------------------------------------------------------------------------------------------------------------------
   Total noninterest expense                                                           11,713                   --         29,471
- ------------------------------------------------------------------------------------------------------------------------------------
 Income before income taxes                                                             9,419                   --         17,791
 Income taxes                                                                           3,671                   --          6,763
- ------------------------------------------------------------------------------------------------------------------------------------

- ------------------------------------------------------------------------------------------------------------------------------------
   Net Income                                                                         $ 5,748           $       --        $11,028
====================================================================================================================================
Weighted Average Shares Outstanding
  Basic                                                                                10,243                              43,684
  Diluted                                                                              10,337                              44,019

Earnings Per Share
  Basic                                                                                  0.56                                0.25
  Diluted                                                                                0.56                                0.25


See accompanying notes to unaudited pro forma condensed combined financial statements




Unaudited Pro Forma Condensed Combined Statement of Income
For the Three Months Ended March 31, 1999



                                                                                          Pioneer
                                                                                         American                             NBT
                                                                                          Holding                             BSB
                                                                               NBT        Company         Pro Forma        Combined
                                                                           Bancorp Inc.    Corp.          Adjustments      Pro Forma
                                                                           ------------    -----          -----------      ---------

                                                                                                                 
Interest and fee income:
 Loan                                                                         $22,679        $4,812        $       --        $27,491
 Securities                                                                     8,465         2,291                --         10,756
 Other                                                                            458            82                --            540
 -----------------------------------------------------------------------------------------------------------------------------------
   Total interest and fee income:                                              31,602         7,185                --         38,787
 -----------------------------------------------------------------------------------------------------------------------------------

Interest expense:
 Deposits                                                                      11,006         2,729                --         13,735
 Borrowings                                                                     2,878           968                --          3,846
 -----------------------------------------------------------------------------------------------------------------------------------
  Total interest expense                                                       13,884         3,697                --         17,581
 -----------------------------------------------------------------------------------------------------------------------------------
 Net interest income                                                           17,718         3,488                --         21,206
 Provision for loan losses                                                      1,120            75                --          1,195
 -----------------------------------------------------------------------------------------------------------------------------------
 Net interest income after provision for loan losses                           16,598         3,413                --         20,011
 -----------------------------------------------------------------------------------------------------------------------------------

Noninterest income:
 Trust                                                                            835            --                --            835
 Service charges on deposit accounts                                            1,408           517                --          1,925
 Net security gains (losses)                                                      668            --                --            668
 Other                                                                          1,365           126                --          1,491
 -----------------------------------------------------------------------------------------------------------------------------------
  Total noninterest income                                                      4,276           643                --          4,919
 -----------------------------------------------------------------------------------------------------------------------------------


Noninterest expense:
  Salaries and employee benefits                                                5,970         1,331                --          7,301
  Office supplies and postage                                                     637           145                --            782
  Occupancy                                                                     1,024           285                --          1,309
  Equipment                                                                       947           242                --          1,189
  Professional fees and outside services                                          697           183                --            880
  Data processing and communications                                              972           118                --          1,090
  Amortization of intangible assets                                               329            10                --            339
  Other operating                                                               1,240           559                --          1,799
 -----------------------------------------------------------------------------------------------------------------------------------
   Total noninterest expense                                                   11,816         2,873                --         14,689
 -----------------------------------------------------------------------------------------------------------------------------------
 Income before income taxes                                                     9,058         1,183                --         10,241
 Income taxes                                                                   3,282           300                --          3,582
 -----------------------------------------------------------------------------------------------------------------------------------

 -----------------------------------------------------------------------------------------------------------------------------------
   Net Income                                                                 $ 5,776        $  883        $       --        $ 6,659
 ===================================================================================================================================


Weighted Average Shares Outstanding
  Basic                                                                        17,860         2,921                           23,132
  Diluted                                                                      18,104         2,947                           23,423


Earnings Per Share
  Basic                                                                          0.32          0.30                             0.29
  Diluted                                                                        0.32          0.30                             0.28



                                                                                                                              NBT
                                                                                                                              BSB
                                                                                                                            Pioneer
                                                                                        BSB              Pro Forma         Combined
                                                                                   Bancorp, Inc.         Adjustments       Pro Forma
                                                                                   -------------         -----------       ---------
                                                                                                                 
Interest and fee income:
 Loan                                                                               $ 35,463            $       --           $62,954
 Securities                                                                            6,838                    --            17,594
 Other                                                                                   204                    --               744
- ------------------------------------------------------------------------------------------------------------------------------------
   Total interest and fee income:                                                     42,505                    --            81,292
- ------------------------------------------------------------------------------------------------------------------------------------

Interest expense:
 Deposits                                                                             17,927                    --            31,662
 Borrowings                                                                            3,466                    --             7,312
- ------------------------------------------------------------------------------------------------------------------------------------
  Total interest expense                                                              21,393                    --            38,974
- ------------------------------------------------------------------------------------------------------------------------------------
 Net interest income                                                                  21,112                    --            42,318
 Provision for loan losses                                                             3,461                    --             4,656
- ------------------------------------------------------------------------------------------------------------------------------------
 Net interest income after provision for loan losses                                  17,651                    --            37,662
- ------------------------------------------------------------------------------------------------------------------------------------

Noninterest income:
 Trust                                                                                   251                    --             1,086
 Service charges on deposit accounts                                                   1,000                    --             2,925
 Net security gains (losses)                                                            (401)                   --               267
 Other                                                                                 1,539                    --             3,030
- ------------------------------------------------------------------------------------------------------------------------------------
  Total noninterest income                                                             2,389                    --             7,308
- ------------------------------------------------------------------------------------------------------------------------------------


Noninterest expense:
  Salaries and employee benefits                                                       5,081                    --            12,382
  Office supplies and postage                                                            433                    --             1,215
  Occupancy                                                                              773                    --             2,082
  Equipment                                                                              427                    --             1,616
  Professional fees and outside services                                               1,331                    --             2,211
  Data processing and communications                                                     490                    --             1,580
  Amortization of intangible assets                                                       96                    --               435
  Other operating                                                                      2,533                    --             4,332
- ------------------------------------------------------------------------------------------------------------------------------------
   Total noninterest expense                                                          11,164                    --            25,853
- ------------------------------------------------------------------------------------------------------------------------------------
 Income before income taxes                                                            8,876                    --            19,117
 Income taxes                                                                          3,340                    --             6,922
- ------------------------------------------------------------------------------------------------------------------------------------

- ------------------------------------------------------------------------------------------------------------------------------------
   Net Income                                                                       $  5,536            $       --           $12,195
====================================================================================================================================


Weighted Average Shares Outstanding
  Basic                                                                               10,071                                  43,274
  Diluted                                                                             10,341                                  44,105


Earnings Per Share
  Basic                                                                                 0.55                                    0.28
  Diluted                                                                               0.54                                    0.28

See accompanying notes to unaudited pro forma condensed combined financial statements






Unaudited Pro Forma Condensed Combined Statement of Income
For the Year Ended December 31, 1999



                                                                                        Pioneer
                                                                                        American                         NBT
                                                                                        Holding                   Pioneer American
                                                                            NBT          Company     Pro Forma        Combined
                                                                        Bancorp Inc.       Corp.     Adjustments      Pro Forma
                                                                        ------------       -----     -----------      ---------
                                                                                                                
Interest and fee income:
 Loans                                                                     $ 96,235        $19,661   $       --        $115,896
 Securities                                                                  38,166          9,491           --          47,657
 Other                                                                          988            237           --           1,225
- -------------------------------------------------------------------------------------------------------------------------------
   Total interest and fee income:                                           135,389         29,389           --         164,778
- -------------------------------------------------------------------------------------------------------------------------------

Interest expense:
 Deposits                                                                    46,067         10,519           --          56,586
 Borrowings                                                                  14,515          4,379           --          18,894
- -------------------------------------------------------------------------------------------------------------------------------
  Total interest expense                                                     60,582         14,898           --          75,480
- -------------------------------------------------------------------------------------------------------------------------------
 Net interest income                                                         74,807         14,491           --          89,298
 Provision for loan losses                                                    5,070            370           --           5,440
- -------------------------------------------------------------------------------------------------------------------------------
 Net interest income after provision for loan losses                         69,737         14,121           --          83,858
- -------------------------------------------------------------------------------------------------------------------------------

Noninterest income:
 Trust                                                                        3,305             --           --           3,305
 Service charges on deposit accounts                                          6,303          1,635           --           7,938
 Net security gains (losses)                                                  1,716             88           --           1,804
 Other                                                                        5,097          1,108           --           6,205
- -------------------------------------------------------------------------------------------------------------------------------
  Total noninterest income                                                   16,421          2,831           --          19,252
- -------------------------------------------------------------------------------------------------------------------------------


Noninterest expense:
  Salaries and employee benefits                                             25,213          5,291           --          30,504
  Office supplies and postage                                                 2,436            534           --           2,970
  Occupancy                                                                   4,317          1,062           --           5,379
  Equipment                                                                   4,230            990           --           5,220
  Professional fees and outside services                                      3,325          1,005           --           4,330
  Data processing and communications                                          4,091            437           --           4,528
  Amortization of intangible assets                                           1,278             39           --           1,317
  Merger and acquisition charges                                                798             --           --             798
  Other operating                                                             5,812          2,024           --           7,836
- -------------------------------------------------------------------------------------------------------------------------------
   Total noninterest expense                                                 51,500         11,382           --          62,882
- -------------------------------------------------------------------------------------------------------------------------------
 Income before income taxes                                                  34,658          5,570           --          40,228
 Income taxes                                                                12,483          1,488           --          13,971
- -------------------------------------------------------------------------------------------------------------------------------

- -------------------------------------------------------------------------------------------------------------------------------
   Net Income                                                              $ 22,175        $ 4,082   $       --        $ 26,257
===============================================================================================================================


Weighted Average Shares Outstanding
  Basic                                                                      17,851          2,902                       23,089
  Diluted                                                                    18,095          2,929                       23,382


Earnings Per Share
  Basic                                                                        1.24           1.41                         1.14
  Diluted                                                                      1.23           1.39                         1.12



                                                                                                                            NBT
                                                                                                                            BSB
                                                                                                                          Pioneer
                                                                                         BSB           Pro Forma          Combined
                                                                                       Bancorp, Inc.     Adjustments     Pro Forma
                                                                                       -------------     -----------     ---------
                                                                                                                   
Interest and fee income:
 Loans                                                                              $ 151,001           $       --          $266,897
 Securities                                                                            25,038                   --            72,695
 Other                                                                                    682                   --             1,907
- ------------------------------------------------------------------------------------------------------------------------------------
   Total interest and fee income:                                                     176,721                   --           341,499
- ------------------------------------------------------------------------------------------------------------------------------------

Interest expense:
 Deposits                                                                              75,542                   --           132,128
 Borrowings                                                                            14,034                   --            32,928
- ------------------------------------------------------------------------------------------------------------------------------------
  Total interest expense                                                               89,576                   --           165,056
- ------------------------------------------------------------------------------------------------------------------------------------
 Net interest income                                                                   87,145                   --           176,443
 Provision for loan losses                                                             19,137                   --            24,577
- ------------------------------------------------------------------------------------------------------------------------------------
 Net interest income after provision for loan losses                                   68,008                   --           151,866
- ------------------------------------------------------------------------------------------------------------------------------------

Noninterest income:
 Trust                                                                                  1,104                   --             4,409
 Service charges on deposit accounts                                                    4,382                   --            12,320
 Net security gains (losses)                                                             (231)                  --             1,573
 Other                                                                                  7,116                   --            13,321
- ------------------------------------------------------------------------------------------------------------------------------------
  Total noninterest income                                                             12,371                   --            31,623
- ------------------------------------------------------------------------------------------------------------------------------------


Noninterest expense:
  Salaries and employee benefits                                                       20,386                   --            50,890
  Office supplies and postage                                                           1,684                   --             4,654
  Occupancy                                                                             2,874                   --             8,253
  Equipment                                                                             1,733                   --             6,953
  Professional fees and outside services                                                6,001                   --            10,331
  Data processing and communications                                                    1,930                   --             6,458
  Amortization of intangible assets                                                       386                   --             1,703
  Merger and acquisition charges                                                        5,408                   --             6,206
  Other operating                                                                      10,261                   --            18,097
- ------------------------------------------------------------------------------------------------------------------------------------
   Total noninterest expense                                                           50,663                   --           113,545
- ------------------------------------------------------------------------------------------------------------------------------------
 Income before income taxes                                                            29,716                   --            69,944
 Income taxes                                                                          11,491                   --            25,462
- ------------------------------------------------------------------------------------------------------------------------------------

- ------------------------------------------------------------------------------------------------------------------------------------
   Net Income                                                                       $  18,225           $       --          $ 44,482
====================================================================================================================================


Weighted Average Shares Outstanding
  Basic                                                                                10,138                                 43,365
  Diluted                                                                              10,312                                 44,006


Earnings Per Share
  Basic                                                                                  1.80                                   1.03
  Diluted                                                                                1.77                                   1.01

See accompanying notes to unaudited pro forma condensed combined financial statements





Unaudited Pro Forma Condensed Combined Statement of Income
For the Year Ended December 31, 1998



                                                                                  Pioneer
                                                                                  American                                NBT
                                                                                  Holding                          Pioneer American
                                                                 NBT              Company           Pro Forma           Combined
                                                            Bancorp Inc.           Corp.           Adjustments         Pro Forma
                                                                                                            
Interest and fee income:
 Loans                                                        $ 89,399             $ 19,093             $ -             $ 108,492
 Securities                                                     40,370                8,729               -                49,099
 Other                                                             531                  480               -                 1,011
- -----------------------------------------------------------------------------------------------------------------------------------
   Total interest and fee income:                              130,300               28,302               -               158,602
- -----------------------------------------------------------------------------------------------------------------------------------

Interest expense:
 Deposits                                                       48,058               10,840               -                58,898
 Borrowings                                                     12,359                3,479               -                15,838
- -----------------------------------------------------------------------------------------------------------------------------------
  Total interest expense                                        60,417               14,319               -                74,736
- -----------------------------------------------------------------------------------------------------------------------------------
 Net interest income                                            69,883               13,983               -                83,866
 Provision for loan losses                                       5,729                  420               -                 6,149
- -----------------------------------------------------------------------------------------------------------------------------------
 Net interest income after provision for loan losses            64,154               13,563               -                77,717
- -----------------------------------------------------------------------------------------------------------------------------------

Noninterest income:
 Trust                                                           3,115                    -               -                 3,115
 Service charges on deposit accounts                             5,325                1,404               -                 6,729
 Net security gains (losses)                                     1,056                  511               -                 1,567
 Other                                                           5,417                1,046               -                 6,463
- -----------------------------------------------------------------------------------------------------------------------------------
  Total noninterest income                                      14,913                2,961               -                17,874
- -----------------------------------------------------------------------------------------------------------------------------------


Noninterest expense:
  Salaries and employee benefits                                24,215                5,071               -                29,286
  Office supplies and postage                                    2,523                  506               -                 3,029
  Occupancy                                                      4,132                1,027               -                 5,159
  Equipment                                                      3,599                  773               -                 4,372
  Professional fees and outside services                         3,375                1,027               -                 4,402
  Data processing and communications                             3,796                  483               -                 4,279
  Amortization of intangible assets                              1,275                   39               -                 1,314
  Other operating                                                7,665                2,041               -                 9,706
- -----------------------------------------------------------------------------------------------------------------------------------
   Total noninterest expense                                    50,580               10,967               -                61,547
- -----------------------------------------------------------------------------------------------------------------------------------
 Income before income taxes                                     28,487                5,557               -                34,044
 Income taxes                                                    5,614                1,535               -                 7,149
- -----------------------------------------------------------------------------------------------------------------------------------

- -----------------------------------------------------------------------------------------------------------------------------------
   Net Income                                                 $ 22,873              $ 4,022             $ -              $ 26,895
===================================================================================================================================

Weighted Average Shares Outstanding
  Basic                                                         17,976                2,894                                23,200
  Diluted                                                       18,361                2,953                                23,691

Earnings Per Share
  Basic                                                           1.27                 1.39                                  1.16
  Diluted                                                         1.25                 1.36                                  1.14



                                                                                                          NBT
                                                                                                          BSB
                                                                                                        Pioneer
                                                                        BSB          Pro Forma         Combined
                                                                   Bancorp, Inc.    Adjustments        Pro Forma
                                                                                             
Interest and fee income:
 Loans                                                             $ 139,374              $ -         $ 247,866
 Securities                                                           25,926                -            75,025
 Other                                                                   866                -             1,877
- ----------------------------------------------------------------------------------------------------------------
   Total interest and fee income:                                    166,166                -           324,768
- ----------------------------------------------------------------------------------------------------------------

Interest expense:
 Deposits                                                             72,387                -           131,285
 Borrowings                                                           12,399                -            28,237
- ----------------------------------------------------------------------------------------------------------------
  Total interest expense                                              84,786                -           159,522
- ----------------------------------------------------------------------------------------------------------------
 Net interest income                                                  81,380                -           165,246
 Provision for loan losses                                            12,931                -            19,080
- ----------------------------------------------------------------------------------------------------------------
 Net interest income after provision for loan losses                  68,449                -           146,166
- ----------------------------------------------------------------------------------------------------------------

Noninterest income:
 Trust                                                                   994                -             4,109
 Service charges on deposit accounts                                   3,714                -            10,443
 Net security gains (losses)                                            (851)               -               716
 Other                                                                 4,738                -            11,201
- ----------------------------------------------------------------------------------------------------------------
  Total noninterest income                                             8,595                -            26,469
- ----------------------------------------------------------------------------------------------------------------


Noninterest expense:
  Salaries and employee benefits                                      19,528                -            48,814
  Office supplies and postage                                          1,998                -             5,027
  Occupancy                                                            2,911                -             8,070
  Equipment                                                            1,466                -             5,838
  Professional fees and outside services                               4,086                -             8,488
  Data processing and communications                                   2,027                -             6,306
  Amortization of intangible assets                                      386                -             1,700
  Other operating                                                      9,581                -            19,287
- ----------------------------------------------------------------------------------------------------------------
   Total noninterest expense                                          41,983                -           103,530
- ----------------------------------------------------------------------------------------------------------------
 Income before income taxes                                           35,061                -            69,105
 Income taxes                                                         13,542                -            20,691
- ----------------------------------------------------------------------------------------------------------------

- ----------------------------------------------------------------------------------------------------------------
   Net Income                                                       $ 21,519              $ -          $ 48,414
================================================================================================================

Weighted Average Shares Outstanding
  Basic                                                               10,006                             43,212
  Diluted                                                             10,365                             44,421

Earnings Per Share
  Basic                                                                 2.15                               1.12
  Diluted                                                               2.08                               1.09

See accompanying notes to unaudited pro forma condensed combined financial statements





Unaudited Pro Forma Condensed Combined Statement of Income
For the Year Ended December 31, 1997




                                                                                  Pioneer                                 NBT
                                                                                  American                         Pioneer American
                                                                 NBT              Holding           Pro Forma           Combined
                                                            Bancorp Inc.       Company Corp.       Adjustments         Pro Forma
                                                                                                            
Interest and fee income:
 Loans                                                       $ 81,688             $ 18,101             $ -              $ 99,789
 Securities                                                    38,536                8,086               -                46,622
 Other                                                            607                  320               -                   927
- -----------------------------------------------------------------------------------------------------------------------------------
   Total interest and fee income:                             120,831               26,507               -               147,338
- -----------------------------------------------------------------------------------------------------------------------------------

Interest expense:
 Deposits                                                      45,629               11,337               -                56,966
 Borrowings                                                    10,418                1,508               -                11,926
- -----------------------------------------------------------------------------------------------------------------------------------
  Total interest expense                                       56,047               12,845               -                68,892
- -----------------------------------------------------------------------------------------------------------------------------------
 Net interest income                                           64,784               13,662               -                78,446
 Provision for loan losses                                      4,285                  535               -                 4,820
- -----------------------------------------------------------------------------------------------------------------------------------
 Net interest income after provision for loan losses           60,499               13,127               -                73,626
- -----------------------------------------------------------------------------------------------------------------------------------

Noninterest income:
 Trust                                                          2,675                    -               -                 2,675
 Service charges on deposit accounts                            4,942                1,397               -                 6,339
 Net security gains (losses)                                     (123)                 157               -                    34
 Other                                                          3,973                  907               -                 4,880
- -----------------------------------------------------------------------------------------------------------------------------------
  Total noninterest income                                     11,467                2,461               -                13,928
- -----------------------------------------------------------------------------------------------------------------------------------


Noninterest expense:
  Salaries and employee benefits                               22,111                5,040               -                27,151
  Office supplies and postage                                   2,250                  507               -                 2,757
  Occupancy                                                     3,754                1,026               -                 4,780
  Equipment                                                     2,632                  685               -                 3,317
  Professional fees and outside services                        2,485                  900               -                 3,385
  Data processing and communications                            2,966                  456               -                 3,422
  Amortization of intangible assets                             1,505                   39               -                 1,544
  Other operating                                               6,677                1,427               -                 8,104
- -----------------------------------------------------------------------------------------------------------------------------------
   Total noninterest expense                                   44,380               10,080               -                54,460
- -----------------------------------------------------------------------------------------------------------------------------------
 Income before income taxes                                    27,586                5,508               -                33,094
 Income taxes                                                   9,406                1,500               -                10,906
- -----------------------------------------------------------------------------------------------------------------------------------

- -----------------------------------------------------------------------------------------------------------------------------------
   Net Income                                                $ 18,180              $ 4,008             $ -              $ 22,188
===================================================================================================================================

Weighted Average Shares Outstanding
  Basic                                                        17,095                2,850                                22,239
  Diluted                                                      17,393                2,939                                22,698

Earnings Per Share
  Basic                                                          1.06                 1.41                                  1.00
  Diluted                                                        1.05                 1.36                                  0.98



                                                                                                          NBT
                                                                                                          BSB
                                                                                                        Pioneer
                                                                        BSB           Pro Forma         Combined
                                                                   Bancorp, Inc.     Adjustments       Pro Forma
                                                                                             
Interest and fee income:
 Loans                                                             $ 120,750             $ -          $ 220,539
 Securities                                                           20,398               -             67,020
 Other                                                                   200               -              1,127
- ----------------------------------------------------------------------------------------------------------------
   Total interest and fee income:                                    141,348               -            288,686
- ----------------------------------------------------------------------------------------------------------------

Interest expense:
 Deposits                                                             60,180               -            117,146
 Borrowings                                                           11,272               -             23,198
- ----------------------------------------------------------------------------------------------------------------
  Total interest expense                                              71,452               -            140,344
- ----------------------------------------------------------------------------------------------------------------
 Net interest income                                                  69,896               -            148,342
 Provision for loan losses                                            10,814               -             15,634
- ----------------------------------------------------------------------------------------------------------------
 Net interest income after provision for loan losses                  59,082               -            132,708
- ----------------------------------------------------------------------------------------------------------------

Noninterest income:
 Trust                                                                   709               -              3,384
 Service charges on deposit accounts                                   3,297               -              9,636
 Net security gains (losses)                                             380               -                414
 Other                                                                 3,762               -              8,642
- ----------------------------------------------------------------------------------------------------------------
  Total noninterest income                                             8,148               -             22,076
- ----------------------------------------------------------------------------------------------------------------


Noninterest expense:
  Salaries and employee benefits                                      17,121               -             44,272
  Office supplies and postage                                          1,886               -              4,643
  Occupancy                                                            2,547               -              7,327
  Equipment                                                            1,378               -              4,695
  Professional fees and outside services                               2,716               -              6,101
  Data processing and communications                                   1,358               -              4,780
  Amortization of intangible assets                                      386               -              1,930
  Other operating                                                      9,548               -             17,652
- ----------------------------------------------------------------------------------------------------------------
   Total noninterest expense                                          36,940               -             91,400
- ----------------------------------------------------------------------------------------------------------------
 Income before income taxes                                           30,290               -             63,384
 Income taxes                                                         11,641               -             22,547
- ----------------------------------------------------------------------------------------------------------------

- ----------------------------------------------------------------------------------------------------------------
   Net Income                                                       $ 18,649             $ -           $ 40,837
================================================================================================================

Weighted Average Shares Outstanding
  Basic                                                                9,905                             42,049
  Diluted                                                             10,258                             43,214

Earnings Per Share
  Basic                                                                 1.88                               0.97
  Diluted                                                               1.82                               0.94



See accompanying notes to unaudited pro forma condensed combined financial statements




      NOTES TO UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL STATEMENTS

(1)  Pro  forma  earnings  per  share  have been  calculated  on the  applicable
     weighted average number of shares of NBT plus the additional  shares of NBT
     assumed to be issued in the mergers in exchange  for the  weighted  average
     outstanding  shares of Pioneer American and BSB for each applicable  period
     based on the exchange ratios of 1.805 and 2.0, respectively.


(2)  Pro  forma  entry  to  retire  treasury  stock  held  by  Pioneer  American
     (approximately 71,060 shares having a par value of $1.00 per share):


                                                                                         
     Common Stock                                                                               71,060
     Paid in Capital                                                                         1,658,739
         Treasury Stock                                                                      1,729,799


     Pro forma entry to issue 1.805  shares of NBT common  stock in exchange for
     each share of Pioneer  American  common stock.  The par value of NBT common
     stock to be issued is determined as follows:


                                                                                         
     NBT common stock issued at March 31, 2000                                              18,623,435

     NBT common stock issued in exchange for Pioneer American common stock after
     retirement of Pioneer American treasury stock (2,864,307 shares of Pioneer
     American common stock times conversion ratio of 1.805)                                  5,170,074
                                                                                           -----------

     Combined pro forma total shares of common stock issued                                 23,793,509

     Par value per share of common stock                                                   $       .01
                                                                                           -----------

     Combined pro forma total par value                                                    $   237,935
                                                                                           ===========


     Actual par value of common stock at March 31, 2000:

     NBT/BSB combined pro forma (note 1)                                                   $   186,234
     Pioneer American (after retirement of treasury shares)                                  2,864,307
                                                                                           -----------

     Total                                                                                 $ 3,050,541
                                                                                           ===========

     Required decrease in par value                                                        $ 2,812,606
                                                                                           ===========


     Entry to conform par value of common stock:

     Common stock                                                                            2,812,606
         Paid in Capital                                                                     2,812,606

     Summary of pro forma entries above:

     Common Stock                                                                            2,883,666
         Paid in Capital                                                                     1,153,867
         Treasury Stock                                                                      1,729,799




(3)  Pro  forma  entry  to  retire  treasury  stock  held by BSB  (approximately
     1,174,216 shares having a par value of $.01 per share):


                                                                                          
     Common Stock                                                                                11,742
     Paid in Capital                                                                         13,445,258
         Treasury Stock                                                                      13,457,000


     BSB common stock issued at March 31, 2000                                               11,430,761
     Less treasury stock retired above                                                       (1,174,216)
                                                                                            -----------

     BSB common stock issued and outstanding at March 31, 2000                               10,256,545
                                                                                            ===========



     Pro forma  entry to issue 2.0 shares of NBT common  stock in  exchange  for
     each share of BSB common stock:



                                                                                        
     Combined NBT/Pioneer American pro forma common stock issued at March 31, 2000
     (note 2)                                                                               23,793,509

     NBT common stock  issued in exchange for BSB common stock after  retirement
     of BSB's  treasury  stock  (10,256,545  shares of BSB  common  stock  times
     conversion ratio of 2.0)                                                               20,513,090
                                                                                            ----------

     Combined pro forma total shares of common stock issued                                 44,306,599

     Par value per share of NBT common stock                                               $       .01
                                                                                           -----------

     Combined NBT/BSB pro forma total par value                                            $   443,066
                                                                                           ===========


     Actual par value of common stock at March 31, 2000:

     NBT/Pioneer American pro forma (note 2)                                               $   237,935
     BSB (after retirement of treasury shares)                                                 102,566
                                                                                           -----------

     Total                                                                                 $   340,501
                                                                                           ===========

     Required increase in par value                                                        $   102,565
                                                                                           ===========


     Entry to conform par value of common stock:

     Paid in Capital                                                                           102,565
         Common stock                                                                          102,565


     Summary of pro forma entries above:

     Paid in Capital                                                                        13,547,823
         Common Stock                                                                           90,823
         Treasury Stock                                                                     13,457,000






(4)  Authorized, issued and outstanding share information is as follows at March
     31, 2000:



- ------------------------------------------------------------------------------------------------------------------------------
                                       NBT             Pioneer         NBT/Pioneer         BSB                NBT/Pioneer
                                                       American        American Pro forma                     American/BSB Pro
                                                                                                              forma
- ------------------------------------------------------------------------------------------------------------------------------
                                                                                                        
PREFERRED
- ------------------------------------------------------------------------------------------------------------------------------
Authorized                            2,500,000            -              2,500,000          2,500,000              2,500,000
- ------------------------------------------------------------------------------------------------------------------------------
Issued and Outstanding                     -               -                 -                   -                    -
- ------------------------------------------------------------------------------------------------------------------------------

- ------------------------------------------------------------------------------------------------------------------------------
COMMON
- ------------------------------------------------------------------------------------------------------------------------------
Par value                                 $0.01           $1.00               $0.01               $.01                  $0.01
- ------------------------------------------------------------------------------------------------------------------------------
Authorized                           30,000,000      30,000,000          30,000,000         30,000,000            100,000,000
- ------------------------------------------------------------------------------------------------------------------------------
Issued                               18,623,435       2,935,367          23,793,509         11,430,761             44,306,599
- ------------------------------------------------------------------------------------------------------------------------------
Outstanding                          18,100,868       2,864,307          23,270,942         10,256,545             43,784,032
- ------------------------------------------------------------------------------------------------------------------------------

- ------------------------------------------------------------------------------------------------------------------------------



(5)  The unaudited pro forma condensed combined balance sheet at March 31, 2000,
     reflects  anticipated  non-recurring  merger and integration costs for both
     the Pioneer American and BSB mergers. Costs related to the Pioneer American
     merger are  estimated  to be in the range of $4.6  million to $5.6  million
     ($3.3 million to $4.3 million after taxes). Costs related to the BSB merger
     are estimated to be in the range of $16.0  million to $17.0 million  ($11.5
     million to $12.5 million after taxes).  These estimates  include  primarily
     investment banking, legal, accounting, printing, data processing and system
     integration costs, and employee and contract termination costs. Anticipated
     merger and integration cost estimates are not included in the unaudited pro
     forma  condensed  combined  statements  of  income  for any of the  periods
     presented.

     The pro forma  statements do not reflect  potential  expense  reductions or
     revenue enhancements  expected to be realized subsequent to consummation of
     the mergers.

     The unaudited pro forma condensed  combined balance sheet at March 31, 2000
     only reflects merger and integration costs related to the Lake Ariel merger
     that were incurred  through March 31, 2000.  It is  anticipated  that there
     will be an additional $5.0 million of merger and integration costs incurred
     in the future in connection  with the Lake Ariel merger.  These  additional
     costs are not  recognized  in the unaudited  pro forma  condensed  combined
     balance sheet at March 31, 2000.

     The entries to record the anticipated  merger and integration  costs on the
     unaudited pro forma condensed combined balance sheet are as follows:


                                                                                        
    BSB
    Current tax receivable                                                                   4,500,000
    Retained earnings                                                                       12,000,000
        Other liabilities                                                                   16,500,000


    Pioneer American
    Current tax receivable                                                                   1,300,000
    Retained earnings                                                                        3,800,000
        Other liabilities                                                                    5,100,000






                                    SIGNATURE

     Pursuant to the  requirements  of the Securities  Exchange Act of 1934, the
Registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned hereunto duly authorized.

                                           NBT BANCORP INC.


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

Date:  July 24, 2000









                                  EXHIBIT INDEX

23.1              Consent of KPMG LLP

23.2              Consent of PricewaterhouseCoopers LLP