sentences:  In January 2008, Bronco Drilling acquired a 25% equity interest in Challenger and added several rigs to the overall fleet.In addition to his chairmanship of Challenger Limited, Tatanaki also co-founded Challenger Group Ltd., which is the parent company of several commercial vehicles operating in the Middle East and Africa.He is actively involved in the management and strategic planning of the Group's various enterprises, which include urban development, tourism, civil construction and IT.