Encana Corp. said Tuesday that it has ended negotiations with Chinese state-owned oil company PetroChina International Investment Co. Ltd. on a joint venture in a major shale gas region in British Columbia.

The initial memorandum of understanding between the two companies was considered the marquee agreement of 11 deals signed in one afternoon last June 25 in Toronto as part of a summit on Sino-Canadian economic friendship and cooperation. The Encana/PetroChina agreement was among the largest of several recent deals by Chinese state-owned companies looking to acquire Canadian oil and gas assets, as reported last November in The American Lawyer.