OKLAHOMA CITY -- Chesapeake Energy said Monday it will sell a 50 percent stake in oil and natural gas-rich land in Oklahoma to Chinese oil company Sinopec for $1.02 billion as the natural gas producer continues selling off assets to repay debt.Chesapeake is the second-largest producer of natural gas in the U.S. after Irving-based Exxon Mobil. Hurt by low natural gas prices, it has sold more than $10 billion in assets to pay down debt incurred as it rushed to buy land and other assets. It's also increasingly focused on more lucrative oil and gas liquids.The company posted a $940 million loss last year because of a big charge to write down the value of its natural gas-producing property.The deal with Sinopec "moves us further along in achieving our asset sales goals and secures an excellent partner to share the capital costs required to actively develop this very large, liquids-rich resource play," said Steven Dixon, Chesapeake's chief operating officer.The company plans to sell $4 billion to $7 billion in assets this year.For Sinopec, the biggest refiner in Asia, investing with Chesapeake gives it a bigger foothold in North America. It and other state-owned companies have been expanding in recent years with acquisitions outside of Asia as they seek access to resources needed to fuel their economies.Canadian and U.S. authorities recently approved the acquisition of Canada's Nexen Inc. by China's CNOOC for $15.1 billion. China's state-owned PetroChina in December announced that it was paying $2.21 billion for a 49.9 percent stake in acreage in Alberta controlled by Canada's Encana Corp.Canadian authorities have said they would be unlikely to approve more outright purchases, while welcoming joint ventures.The joint venture between Sinopec and Chesapeake involves 850,000 acres in the Mississippi Lime play in northern Oklahoma. It produced about 34,000 barrels of oil equivalent per day during the most recent quarter, Chesapeake said. As of the end of the year there were about 140 million barrels of oil equivalent in proven reserves on the land.Chesapeake said it will get 93 percent of the money when the deal closes, which is expected in the second quarter. It will be paid the rest of the money after other conditions are met.Future exploration and development cost will be shared by the two companies, with Chesapeake operating the project and conducting all leasing, drilling, completion, operations, and marketing.