FACTBOX-Key facts about Canada's Nexen

Dec 7 (Reuters) - Canada approved state-owned CNOOC Ltd's $15.1 billion bid for Nexen Inc on Friday, allowing China's biggest takeover of a foreign company to go ahead.

Here are some key facts about the takeover target:

- Nexen is Canada's fifth-largest independent oil explorer and producer, and the eighth biggest energy company by market capitalization in the Toronto stock Exchange's energy sector, based on Thursday's late-day trading prices.

- As of 2011, Nexen had about 2.3 billion barrels of oil equivalent of proved and probable reserves

- The company started in Western Canada as a unit of Occidental Petroleum Corp, but is now fully independent. It operates in the Gulf of Mexico, Colombia, the North Sea, Yemen and offshore West Africa. Its assets include conventional oil and gas, oil sands and shale gas

- Nexen produced 207,000 barrels of oil equivalent per day (boe/d) in 2011, including about 45,000 boe/d in the northern Alberta oil sands, where it has stakes in the Long Lake and Syncrude Canada projects

- Nexen is the second-largest oil producer in the North Sea, where it operates the Buzzard platform. In 2011, its share of Buzzard production was 62,400 boe/d. In the Gulf of Mexico, Nexen's 2011 share was 22,600 boe/d.

- Headquartered in Calgary, Alberta, and traded on the Toronto and New York stock exchanges, Nexen has about 3,000 employees, including about 2,000 in Canada, 500 in the United Kingdom and 330 in the United States.

- Nexen's market capitalization was C$12.47 billion as of Friday's close.

Source: Company filings, company website, Thomson Reuters data.

($1=$0.99 Canadian)

(Reporting by Allison Martell; Editing by Peter Galloway)