As filed with the Securities and Exchange Commission on January 22, 2010
Registration No. 333-152859

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

POST-EFFECTIVE AMENDMENT TO FORM S-8
REGISTRATION STATEMENT
UNDER THE SECURITIES ACT OF 1933

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Post-Effective Amendment to Form S-8 Registration Statement No. 333-152859

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CNB FINANCIAL CORP.
-------------------
(Exact name of registrant as specified in its articles of organization)

MASSACHUSETTS 20-3801620
------------- ----------
(State or other jurisdiction of (I.R.S. Employer Identification No.)
incorporation or organization)

c/o United Financial Bancorp, Inc.
95 Elm Street
West Springfield, Massachusetts 01089
(413) 787-1700
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(Address, including zip code, and telephone number,
including area code, of registrant's principal executive offices)

CNB Financial Corp. 2008 Equity Incentive Plan
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(Full title of the plan)

Richard B. Collins
President and Chief Executive Officer
United Financial Bancorp, Inc.
95 Elm Street
West Springfield, Massachusetts 01089
(413) 787-1700
(Name, address, including zip code, and telephone number,
including area code, of agent for service)

Indicate by check mark whether the registrant is a large accelerated filer, an
accelerated filer, a non-accelerated filer, or a smaller reporting company. See
the definitions of "large accelerated filer," "accelerated filer" and "smaller
reporting company" in Rule 12b-2 of the Exchange Act.

Large accelerated filer [ ] Accelerated filer [ ]
Non-accelerated filer [ ] Smaller reporting company |X|
(Do not check if a smaller reporting company)

2
EXPLANATORY NOTE

This Post-Effective Amendment relates to the following Registration
Statements on Form S-8 (collectively, the "Registration Statements"):

Registration Statement No. 333-152859 registering 100,000 shares of CNB
Financial Corp. common stock, par value $1.00 per share ("CNB Financial Common
Stock") in connection with the CNB Financial Corp. 2008 Equity Incentive Plan;
and

Pursuant to the Agreement and Plan of Merger, dated as of June 25,
2009, by and between United Financial Bancorp, Inc. and CNB Financial, CNB
Financial merged with and into United Financial with CNB Financial ceasing to
exist and United Financial continuing as the surviving corporation. The merger
became effective at 11:58 p.m. on November 30, 2009.

Upon the closing of the merger, each outstanding share of CNB Financial
Common Stock was converted into the right to receive, at the election of the
shareholder, either $10.75 per share in cash or 0.8257 shares of United
Financial common stock, provided that the 50% of the CNB Financial Common Stock
would be converted into cash. All CNB Financial shareholder elections were
subject to the allocation and proration procedures set forth in the merger
agreement. Shares of CNB Financial Common Stock are no longer quoted on the OTC
Bulletin Board.

As a result of the merger, CNB Financial has terminated all offerings
of securities pursuant to the Registration Statements. In accordance with the
undertaking made by CNB Financial in the Registration Statements to remove from
registration by means of a post-effective amendment any of its securities being
registered under the Registration Statements that remain unsold at the
termination of the offering, United Financial (as successor to CNB Financial)
hereby terminates the effectiveness of the Registration Statements and
deregisters any and all shares of CNB Financial Common Stock originally reserved
for issuance under the plans covered by the Registration Statements and
registered under the Registration statements, which remain unsold or unissued as
of the date hereof.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, United
Financial Bancorp, Inc. (as successor to CNB Financial Corp.) certifies that it
has reasonable grounds to believe that it meets all of the requirements for
filing on Form S-8 and has duly caused this post-effective amendment to the
Registration Statements to be signed on its behalf by the undersigned, thereunto
duly authorized in the City of West Springfield, Massachusetts, on this 21st day
of January, 2010.

UNITED FINANCIAL BANCORP, INC.
(as successor to CNB Financial Corp.)

By: /s/ Richard B. Collins
-----------------------------------
Richard B. Collins
President
(principal executive officer)

Pursuant to the requirements of the Securities Act, this post-effective
amendment to the Registration Statements has been signed by the following
persons in the capacities and on the dates indicated.

Name Title Date
- ---- ----- ----

/s/ Richard B. Collins President and Chief Executive Officer January 21, 2010
- ------------------------------------ (principal executive officer)
Richard B. Collins

/s/ Mark A. Roberts Treasurer and Chief Financial Officer January 21, 2010
- ------------------------------------ (principal financial and accounting
Mark A. Roberts officer)

/s/ Paula A. Aiello Director January 21, 2010
- ------------------------------------
Paula A. Aiello

/s/ Michael F. Crowley Director January 21, 2010
- ------------------------------------
Michael F. Crowley

/s/ Carol Moore Cutting Director January 21, 2010
- ------------------------------------
Carol Moore Cutting

/s/ Carol A. Leary Director January 21, 2010
- ------------------------------------
Carol A. Leary

/s/ G. Todd Marchant Director January 21, 2010
- ------------------------------------
G. Todd Marchant

/s/ Kevin E. Ross Director January 21, 2010
- ------------------------------------
Kevin E. Ross

/s/ Robert A. Stewart, Jr. Director January 21, 2010
- ------------------------------------
Robert A. Stewart, Jr.

/s/ Thomas H. Themistos Director January 21, 2010
- ------------------------------------
Thomas H. Themistos

/s/ Michael F. Werenski Director January 21, 2010
- ------------------------------------
Michael F. Werenski