Exhibit 10.45


AMENDMENT NO. 3 TO EMPLOYMENT
AGREEMENT


Dated as of December
13, 2006


Reference is made
to that certain Amended and Restated Employment Agreement dated as of January 1,
2004, as amended by Amendment No. 1 thereto dated as of December 31, 2004 and
Amendment No. 2 thereto dated as of October 17, 2006 (the “Agreement”), by and
among Enterprise Bancorp, Inc. (the “Company”) and Enterprise Bank and Trust
Company (the “Bank” and together with the Company, the “Employers”) and Richard
W. Main (the “Executive”).


WHEREAS, the
Employers and the Executive have previously agreed to certain changes to the
Agreement, which are to become effective as of January 1, 2007 (the “Effective
Date”) and are reflected in said Amendment No. 2 referenced above;


AND WHEREAS, the
Employers and the Executive are in mutual agreement that certain additional
changes to the Agreement, which would also become effective as of the Effective
Date, would be advisable;


NOW, THEREFORE, in
consideration of the premises and mutual covenants herein contained and for
other good and valuable consideration, the receipt and adequacy of which is
hereby acknowledged, the Employers and the Executive hereby agree as follows:


Effective
as of the Effective Date, the Agreement shall be further amended, such that the
various provisions of the Agreement referenced below shall be amended as set
forth below.


Amendment to Section 1.8.  Section 1.8 shall be amended and restated in
its entirety to read as follows:


1.8           “Highest Annual Compensation” means,
as determined as of any Date of Termination, the sum of (a) the highest per
annum rate of base salary paid by the Employers to the Executive at any time
during the Term of Employment prior to such Date of Termination and (b) the
highest annual cash performance bonus or other annual cash incentive
compensation paid by the Employers to the Executive, including all such cash
amounts paid to the Executive individually and as part of an employee or
executive officer group (or which would have been paid but for an election by
the Executive to defer payment to a later period), with respect to any single fiscal
year of the Employers during the Term of Employment prior to such Date of
Termination.


Amendment to Section 1.12.  In Section 1.12, the phrase “attains the age
of 65 years old” contained in the second and third lines thereof shall be
amended and restated in its entirety to read “attains the age of 63 years old”.


Amendment to Section 3.  Section
3 shall be amended and restated in its entirety to read as follows:


3.             Term of Employment.  The term of employment under this Agreement
shall commence as of the Effective Date and, subject to extension as













provided in this Section 3 or earlier termination as
provided under Section 6 of this Agreement, shall continue through March 31,
2008 (the “Term of Employment”).  As of
April 1, 2007 and as of the first day of April in each subsequent year
thereafter during which this Agreement remains in effect (each such day a “Renewal
Date”), a one-year extension of the then current Term of Employment shall
automatically be effected (for example, on April 1, 2007, the Term of
Employment shall be extended from a term ending on March 31, 2008 to a term
ending on March 31, 2009).  Either the
Employers or the Executive may give written notice to the other on or prior to
any given Renewal Date of the intent of the party giving such notice to
terminate this Agreement at the expiration of the two-year period commencing on
such Renewal Date.  Upon the delivery by
either party of any such notice, the Term of Employment shall no longer be
subject to the automatic one-year extension provided for herein, but rather
shall expire upon the conclusion of such final two-year period.


Amendments to Sections 6.1(f), 6.4(f), 6.5(b)(v)
and 6.6(e).  Each
of Sections 6.1(f), 6.4(f), 6.5(b)(v) and 6.6(e) shall be amended and restated
in its entirety to read as follows:


any other compensation
and benefits as may be provided in accordance with the terms and provisions of
any other agreements between the Executive and either of the Employers and any
applicable plans, programs, procedures and practices of the Employers;


The
Agreement, as amended by this Amendment No. 3 as of the Effective Date, is and
shall continue to be in full force and effect and shall not be affected by this
Amendment No. 3, except and only to the extent specified above.


[Remainder of Page Intentionally Blank]



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IN WITNESS WHEREOF, the undersigned Executive has hereunto set his hand
and each of the Employers has caused this Amendment No. 3 to be executed in its
name and on its behalf by a duly authorized officer, in each case as an
instrument under seal and as of the date set forth above.


	
  

  	
  ENTERPRISE
  BANCORP, INC.

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
  /s/ George L.
  Duncan

  
	
   

  	
   

  	
  George L. Duncan

  
	
   

  	
   

  	
  Chairman and Chief Executive Officer

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  ENTERPRISE BANK
  AND TRUST COMPANY

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
  /s/ George L.
  Duncan 

  
	
   

  	
   

  	
  George L. Duncan

  
	
   

  	
   

  	
  Chairman and Chief Executive Officer

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  EXECUTIVE

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
   

  	
  /s/ Richard W.
  Main

  
	
   

  	
   

  	
  Richard W. Main

  



 



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