U.S. oil firm ConocoPhillips has announced it is selling its stake in Kazakhstan's Kashagan oil field to an Indian company for some $5 billion.
Texas-based ConocoPhillips owns 8.4 percent of Kashagan, the world's largest oil field discovered since the early 1970s.
The sale was expected for weeks, but the deal with India's ONGC Videsh came as a surprise, since Kazakhstan's state energy company, KazMunaiGaz, in October expressed an interest in purchasing ConocoPhillips' shares.
The Kashagan field, located in Kazakhstan's sector of the Caspian Sea, has reserves of 38 billion barrels of oil.
Commercial production of oil at Kashagan is due to start in the first half of 2013.
The field is being developed by a consortium that includes oil majors such as Shell, Exxon Mobil, Total, and KazMunaiGaz.
Based on reporting by Reuters and AP