Mike Graham, the Calgary-born president of Encana Corp.'s Canadian division, abruptly resigned Tuesday, effective immediately. Encana spokesman Alan Boras confirmed Mike McAllister, senior vice-president and second in command of the Canadian branch, has been named interim president. Boras said he knew of no reason for Graham's resignation, which comes as the company tries to line up a joint venture partner to help develop its massive Cutbank Ridge shale gas assets in northeastern British Columbia. Encana has set a target of announcing the partner before the end of the first quarter. Last June, PetroChina walked away from a $5.4-billion joint venture deal for the same assets after negotiations with Encana broke down. Eric Marsh, senior vice-president of Encana's U.S. division, said following a presentation at a webcast energy conference in Vail, Colorado, that McAllister is capable of carrying on in Graham's stead. Encana has signalled recently it will be diverting investment from its traditional dry natural gas focus to grow its natural gas liquids business.