Rosetta Resources Inc., Houston, (Nasdaq: ROSE) has amended and restated its senior revolving credit agreement to a maximum credit amount of $600 million from the previous amount of $400 million.

The maturity date of the agreement has been extended by more than two years from April 5, 2010 to July 1, 2012, and the borrowing base has been reset from $400 million to $375 million.

Rosetta also amended and extended its second-lien term loan maturity from July 7, 2010 to Oct. 2, 2012. The amount outstanding remains at $75 million. A 30-day accordion is in place to allow select investors to come in post-close, which would result in a total second-lien raise of $100 million.

Rosetta president and chief executive Randy Limbacher says, “This is a very strong redetermination outcome for our company. Given the current credit environment for our sector, we are particularly pleased that we were able to both raise our maximum credit amount and extend the maturity of our credit agreement. This gives us significant optionality in the form of both access to credit capacity and time that can continue to differentiate us among smaller E&P companies. We are very appreciative of the support given to Rosetta by our bank group through this exercise.”

Rosetta Resources’ operations are concentrated in South Texas, the Rockies and the Sacramento Basin of California.