SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                    FORM 8-K
                                 CURRENT REPORT


                     PURSUANT TO SECTION 13 OR 15(D) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

       Date of Report (Date of earliest event reported): December 22, 2005


                                NBT BANCORP INC.
--------------------------------------------------------------------------------
             (Exact name of registrant as specified in its charter)


             DELAWARE                0-14703                  16-1268674
   ----------------------------    -----------            -------------------
   (State or other jurisdiction    (Commission              (IRS Employer
       of incorporation)           File Number)           Identification No.)


                 52 SOUTH BROAD STREET, NORWICH, NEW YORK 13815
                      -----------------------------------
                    (Address of principal executive offices)

       Registrant's telephone number, including area code: (607) 337-2265
                                 --------------


     Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
                             following provisions:

     [x] Written communication pursuant to Rule 425 under the Securities Act (17
     CFR 230.425)

     [ ] Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17
     CFR 240.14a-12)

     [ ] Pre-commencement communications pursuant to Rule 14d-2(b) under the
     Exchange Act (17 CFR 240.14d-2(b))

     [ ] Pre-commencement communications pursuant to Rule 13e-4(c) under the
     Exchange Act (17 CFR 240.13e-4(c))



                            ITEM 8.01   Other Events
                                        ------------

On December 22, 2005, NBT Bancorp Inc. and CNB Bancorp, Inc. issued a joint
press release announcing the receipt of the required regulatory approvals to
proceed with their proposed merger. A copy of the press release is attached as
Exhibit 99.1 to this Form 8-K.


                 ITEM 9.01   Financial Statements and Exhibits

     {c}  The following is being furnished herewith:



                  
Exhibit No.          Exhibit Description
99.1                 Press release text of NBT Bancorp Inc. and CNB Bancorp, Inc. dated December 22, 2005



                                   SIGNATURES

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.
                                 -----------------------------
                                 (Registrant)


                                 /s/ Michael J. Chewens
                                 -----------------------------
                                 Michael J. Chewens
                                 Senior Executive Vice President,
                                 Chief Financial Officer and Corporate Secretary


Date: December 22, 2005