Penn West Energy Trust (Penn West) is an open-ended investment trust. Its principal undertaking is to issue Trust Units, and to acquire and hold securities of subsidiaries, net profits interests (NPI), royalties, notes and other interests. Its direct and indirect subsidiaries and partnerships carry on the business of acquiring, developing, exploiting and holding interests in petroleum and natural gas properties, and assets related thereto. Penn West Petroleum Ltd. is engaged in the business of oil and natural gas exploitation, development, acquisition and production in Canada. Its operations are managed based on five operating regions: Southern District, Central District, Eastern District, Northwest (NW) Alberta District, and Northern District. On January 11, 2008, Penn West acquired Canetic Resources Trust. On January 10, 2008, Penn West acquired Vault Energy Trust. On July 22, 2008, it acquired Endev Energy Inc. In April 2009, Penn West acquired Reece Energy Exploration Corp.