Canadian uranium producer Cameco Corp and the United Steelworkers union, which represents 535 workers at the world's largest uranium mine and a nearby mill, have agreed to a tentative deal ending a nearly two-week lockout, both sides said on Friday. Shortly after the lockout began, the union said outstanding issues included pensions, benefits and compensation for working in a remote region. The previous contract expired on Dec. 31, 2013. Mike Pulak, a staff representative for United Steelworkers, said workers would begin returning to the McArthur River, Saskatchewan mine and Key Lake mill as early as Friday. There was "pressure exerted on all sides equally" to get a deal, Pulak said in a phone interview.