CALGARY - Chinese state-owned firm CNOOC Ltd. is now officially in control of Calgary oil and gas producer Nexen Inc. (TSX:NXY).

CNOOC's $15.1 billion takeover of Nexen, first announced last July, was completed on Monday, marking China's largest-ever successful overseas acquisition.

Kevin Reinhart, who had been serving as interim CEO since January 2012, will remain in charge of Nexen's operations in the oilsands, B.C. shale fields, North Sea, West Africa and Gulf of Mexico.

CNOOC Ltd. CEO Li Fanrong will serve as chairman of Nexen's new board of directors, which includes members from both the Chinese and Canadian companies.

All of Nexen's existing assets, as well as CNOOC's North and Central American operations, will be managed out of Nexen's Calgary headquarters.

Nexen shares are expected to be delisted from the Toronto Stock Exchange in a few trading days. They will cease being traded on the New York Stock Exchange before markets open Tuesday, and will subsequently be delisted.

The CNOOC-Nexen deal touched off a great deal of controversy about what degree foreign state-owned control of Canadian resources is acceptable.

That the deal came from a Chinese company, in particular, raised concerns in some quarters about doing business with a non-democratic state.

But there was also acknowledgment that Canada does not have the capital necessary to develop its own resources alone, and that overseas investment is needed.

The Conservative government finally decided in December that the deal would be of "net benefit" to Canada under the Investment Canada Act, but that future deals of that type would be held to greater scrutiny.

Ottawa has signalled that deals that give state-owned enterprises control over the oilsands would only be allowed in "exceptional circumstances" from now on, but that partnership deals would continue to bring capital into the sector.

About two weeks ago, Nexen received U.S. government approval.

Earlier Monday, Nexen posted results for its last quarter as an independent company.

Citing impairment charges on natural gas properties in the U.S. and Canada and costs associated with its Long Lake oilsands project, Nexen said its net loss in the three months ended in December was $6 million, or two cents per diluted share.

That was a big reversal from last year's fourth-quarter profit of $43 million or eight cents per share.

Net sales from continuing operations were $1.58 billion, down from $1.66 billion in the same 2011 period.

For the year as a whole, Nexen said income dropped 52 per cent, which primarily reflected "the impact of higher share-based compensation expense as a result of the increase in our share price in part due to the proposed CNOOC Ltd. acquisition and to lower gains from asset dispositions."

Last year, net income included pre-tax gains of $386 million from asset dispositions compared to $194 million in 2012.

Earlier on HuffPost:

Loading Slideshow...
  • The Target

    Nexen is a global oil and gas company that produced 207,000 barrels of oil equivalent per day at the end of 2011. In this April 25, 2012 photo, Nexen chief executive Kevin Reinhart addresses the company's annual meeting in Calgary. <em>With files from The Canadian Press</em>

  • Areas Of Operation

    Only about 30 per cent of Nexen's production comes from its Canadian operations, with the rest coming from offshore platforms in the North Sea, Gulf of Mexico and West Africa.

  • The Buyer

    CNOOC Ltd. is China's largest offshore oil and gas producer and is one of the largest oil and gas exploration and production companies in the world. At the end of 2011, it had 909,000 barrels of oil equivalent per day of production. Its Beijing-based parent, China National Offshore Oil Co., operates directly under the State-owned Assets Supervision and Administration Commission of the State Council of the People's Republic of China. CNOOC Ltd. shares trade on Hong Kong and New York stock exchanges.

  • The Offer

    On July 23, Nexen announced it had accepted CNOOC Ltd.'s all-cash offer of $27.50 per share, worth $15.1 billion. In a circular to shareholders a month later, Nexen revealed it had rejected two earlier CNOOC offers as too low.

  • The Premium

    61 per cent over Nexen's closing share price on the trading day before the deal.

  • Partnership

    CNOOC and Nexen had a relationship well before they announced their deal. In 2011, CNOOC acquired Opti Canada Inc., Nexen's beleaguered partner in the Long Lake oilsands project and the two have been working together on that project since. Later in 2011, CNOOC and Nexen formed a joint venture in the Gulf of Mexico. Around the same time, Nexen also agreed to sell a 40 per cent interest in some of its northeastern B.C. shale natural gas lands to a Japanese-led consortium.

  • The Target

    Progress Energy Resources Corp. (TSX:PRQ) is a mid-sized natural gas producer with daily production of about 50,000 barrels of oil equivalent per day.

  • Areas Of Operation

    Progress is the largest landholder in the Montney shale in northwestern Alberta and northeastern B.C. It is also active in Alberta's Deep Basin.

  • The Buyer

    Petroliam Nasional Bhd, or Petronas, is wholly owned by the government of Malaysia. It has assets and interests in more than 30 countries and is heavily involved in the liquefied natural gas, or LNG, business.

  • The Offer

    Progress announced in late June it had agreed to Petronas' $20.45-per-share takeover offer. A month later, the Malaysian state-owned company sweetened its offer to $22 per share in order to trump a rival bid, bringing the deal's total value to $6 billion.

  • The Premium

    The sweetened offer is worth double what Progress shares traded at the day before the initial takeover deal was announced.

  • Partnership History

    In mid-2011, Progress and Petronas formed a 50-50 partnership to jointly develop the some of the Canadian company's land in the north Montney. The two companies are also partnering on a liquefied natural gas terminal near Prince Rupert, B.C., that will be 60 per cent bigger if the takeover deal