Chesapeake Co-Founder Ward Funding New Energy-Production Company

Tom Ward, who built SandRidge Energy Inc. into a $10 billion company before being fired as chief executive officer in June, has begun a new venture to acquire oil and natural gas wells.

Ward, 54, said he is dipping into his own capital to fund closely held Tapstone Energy. He was removed from Oklahoma City-based SandRidge after investors questioned transactions he and his family members had with the company, days before an activist shareholder was poised to gain control of the board.