A second top executive at Bill Barrett Corp. has left, according to a company filing Tuesday with the US Securities and Exchange Commission.

After the markets closed Monday, Bill Barrett chairman and CEO Fred Barrett stepped down from his positions with the North American oil and natural gas exploration and production company.

Bill Barrett Corp.has signed a purchase and sale agreement with an affiliate of Vanguard Natural Resources LLC for the sale of certain of the company's non-core natural gas assets including all Wind River Basin natural gas producing properties, the Powder River Basin coal bed methane (CBM) assets and a working interest in its Gibson Gulch-Piceance Basin development property.

Bill Barrett Corp. has appointed Carin M. Barth as an independent director. Barth will serve on the Compensation Committee and the Nominating and Corporate Governance Committee of the Board of Directors.

Endurance Energy Ltd., an early-stage exploration and production company focused on the acquisition and development of shallow natural gas assets in the Western Canadian Sedimentary Basin (WCSB), today announced that it has recapitalized the company with an investment from Warburg Pincus, a global private equity firm. 

Following a rise in popularity in the oil and gas upstream sector in 2010, joint venture agreements played a dominant role as a source of low cost funding in 2011—with unconventional resources drawing the most attention, noted analyst at Stifel Nicolaus.