Michael C. Linn has formed MCL Ventures LLC in Houston. The firm is a private investment vehicle that will focus on non-operated interests in ongoing drilling programs of other companies. It also will invest in mineral and royalty interests. Linn, who founded Linn Energy LLC in 2003 in Pittsburgh, retired from the now-Houston-based company on December 31, 2011, although he remains a non-executive director on the board. Under his watch, Linn Energy became the first publicly traded E&P limited liability company in 2006. Today it has an enterprise value of approximately $10 billion.