Exhibit 10.41

AMENDMENT TO SECURITIES PURCHASE AGREEMENT

This AMENDMENT TO SECURITIES PURCHASE AGREEMENT (this “Agreement”), is entered
into July 31, 2008 by and between Brigham Exploration Company, a Delaware
corporation (the “Company”), DLJMB Funding III, Inc., a Delaware corporation
(“MB”), and DLJ ESC II, LP, a Delaware limited partnership (“ESC”) (MB and ESC
are sometimes collectively referred to as “Investors”), DLJ Merchant Banking
Partners III, L.P. (the “Fund”), and the other parties listed on the signature
page hereto (collectively, with the Investors and the Fund, the “CS Entities”).

WHEREAS, the Investors and the Company entered into that certain Securities
Purchase Agreement dated November 1, 2000 (the “Securities Purchase Agreement”)
pursuant to which the Investors acquired one million (1,000,000) shares of
Series A Preferred Stock of the Company (“Shares”) and warrants to acquire six
million, six hundred, sixty-six thousand, six hundred sixty-seven (6,666,667)
shares of Common Stock of the Company (“Warrants”);

WHEREAS, in conjunction with the acquisition of the Shares and Warrants, the
Company granted the Investors the right pursuant to Article VIII of the
Securities Purchase Agreement to nominate one representative of the Investors
appointed by MB to serve as a member of the Board of Directors of the Company
for so long as the Investors or their affiliates own at least ten percent of the
Shares or at least five percent of the outstanding Common Stock of the Company;

WHEREAS, pursuant to that certain Assignment Agreement dated as of December 23,
2002, among the CS Entities and the Company, MB assigned its right to appoint a
director of the Company to the Fund;

WHEREAS, the Investors have determined that it is no longer necessary to retain
this right to nominate a representative to the Board of Directors of the Company
and have agreed with the Company to relinquish that right;

NOW, THEREFORE, in consideration of the premises and the mutual covenants and
agreements herein contained, and intending to be legally bound hereby, the
Company and the Investors hereby agree as follows:

1. Deletion of Covenant to Nominate Board Representative. In order to reflect
the relinquishment by the Fund of the Board nomination right and the Company’s
corresponding covenant to nominate one representative of the Investors to serve
as a member of the Board of Directors of the Company, Article VIII, Board
Representation of the Securities Purchase Agreement is hereby deleted in its
entirety effective as of the date first above written.

2. Continuing Effect. Except as amended hereby or previously amended, the
Securities Purchase Agreement shall continue in full force and effect.

3. Counterparts. This Agreement may be executed by the parties hereto in any
number of counterparts, each of which shall be deemed an original but all of
which shall constitute one and the same Agreement. Each counterpart may consist
of a number of copies hereof, each signed by less than all, but together signed
by all of the parties hereto.

 

1

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

 

IN WITNESS WHEREOF, the parties have executed this Agreement or caused this
Agreement to be executed by their duly authorized representatives, all as of the
day and year first above written.

THE COMPANY:

BRIGHAM EXPLORATION COMPANY

By: /s/ Eugene B. Shepherd, Jr.                       
Name: Eugene B. Shepherd, Jr.
Title: Chief Financial Officer

INVESTORS:

DLJ MERCHANT BANKING PARTNERS III, L.P.
By: DLJ Merchant Banking III, Inc.,
       Its Managing General Partner

By: /s/ William Spiro                                      
Name: William Spiro
Title: Vice President

DLJ MERCHANT BANKING III, INC., as Advisory General Partner on behalf of DLJ
OFFSHORE PARTNERS III, C.V.

By: /s/ William Spiro                                      
Name: William Spiro
Title: Vice President

2

 

2

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

 

DLJ MERCHANT BANKING III, INC., as Advisory General Partner on behalf of DLJ
OFFSHORE PARTNERS III-1, C.V. and as attorney-in-fact for DLJMB III (Bermuda),
L.P., as Associate General Partner of DLJ OFFSHORE PARTNERS III-1, C.V.

By: /s/ William Spiro                                        
Name: William Spiro
Title: Vice President

DLJ MERCHANT BANKING III, INC., as Advisory General Partner on behalf of DLJ
OFFSHORE PARTNERS III-2, C.V. and as attorney-in-fact for DLJMB III (Bermuda),
L.P., as Associate General Partner of DLJ OFFSHORE PARTNERS III-2, C.V.

By: /s/ William Spiro                                        
Name: William Spiro
Title: Vice President

DLJ MERCHANT BANKING III, INC., as General Partner of DLJ Merchant Banking III,
L.P. and as attorney-in-fact for DLJ Merchant Banking III, L.P. as Managing
Limited Partner for and on behalf of DLJ MB PARTNERSIII GmbH & Co. KG

By: /s/ William Spiro                                      
Name: William Spiro
Title: Vice President

DLJ MB GmbH, as General Partner for and on behalf of DLJ MB PARTNERSIII GmbH &
Co. KG

By: /s/ Edward Nadel                                      
Name: Edward Nadel
Title: Director

3

 

3

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

 

MILLENNIUM PARTNERS II,, INC.L.P.
By: DLJ Merchant Banking III, Inc.,
       Its Managing General Partner

By: /s/ William Spiro                                       
Name: William Spiro
Title: Vice President

MBP III PLAN INVESTORS, L.P.
By: DLJ LBO Plans Management Corporation II,
       Its General Partner

By: /s/ William Spiro                                      
Name: William Spiro
Title: Vice President

DLJ ESC II, INC.L.P.
By: DLJ LBO Plans Management Corporation,
       Its General Partner

By: /s/ William Spiro                                     
Name: William Spiro
Title: Vice President

DLJMB FUNDING III, INC.

By: /s/ William Spiro                                     
Name: William Spiro
Title: Vice President

4

 

4