September 27, 2011

Exhibit 10.1

September 27, 2011

BNP Paribas	VIA FAX AND EMAIL
000 Xxxxxxxxxx Xxxx.
Loan Servicing- 0xx Xxxxx
Xxxxxx Xxxx, XX 00000
Attn: Xxxx Xxxxxx
Fax: (000) 000-0000
Email: xxxxxx.xx.xxxxxxx@xxxxxxxx.xxxxxxxxxx.xxx

Re: Fifth Amended and Restated Senior Revolving Credit Agreement dated August 2, 2010, among Petrohawk Energy Corporation (“Petrohawk”), each of the Lenders from time to time party thereto, BNP Paribas, as administrative agent for the Lenders, Bank of America, N.A. and Bank of Montreal, as co-syndication agents for the Lenders, and JPMorgan Chase Bank, N.A. and Xxxxx Fargo Bank, N.A, as co-documentation agents for the Lenders, as amended (the “RCA”)

Ladies and Gentlemen:

Pursuant to Section 2.06(b) of the RCA, Petrohawk hereby notifies you of its election to reduce the Aggregate Maximum Credit Amounts (as defined in the RCA) to Twenty-Five Million Dollars ($25,000,000).  This reduction shall be effective on October 3, 2011.

Yours truly,

Petrohawk Energy Corporation

/s/ Xxxxx X. Xxxx

Xxxxx X. Xxxx

Executive Vice President- Finance and Administration

Cc:  BNP Paribas

0000 Xxxxx Xx., Xxxxx 0000

Xxxxxxx, XX 00000

Attn:  Xxxxx Xxxxxxx

Fax:  (000) 000-0000

Email: xxxxx.xxxxxxx@xxxxxxxx.xxxxxxxxxx.xxx