Enron Crop., the largest US natural gas and electricity wholesaler, will pay $300 millions to form a gas import and distribution joint venture with SK Corp, the South Korean company said. SK, Korea's biggest oil refiner, said it would give up its stake in six gas distributions affiliates SK1 Gas Co, Pusan City Gas Co and Daehan city Gas and three oter unlisted units for a 50 per cent stake in the venture. Enron will pay cash for its half.