The retired Halliburton executive plans to start an oilfield services company. : (Bloomberg) -- Dave Lesar, fresh from retiring as executive chairman of Halliburton Co. at the end of 2018, is working on a new venture in the oil patch with funding from private equity firm CSL Capital Management. Lesar, 65, plans to start an oilfield services company, said Charles Leykum, the founder of Houston-based CSL. A representative for Lesar said he wasn’t immediately able to comment.