US ConocoPhillips is selling all of its 20 percent stocks in Lukoil this year. Lukoil agreed to buy out the US oil company's stake, thus becoming the sole owner of its regional subsidiaries like the Naryanmarneftegaz in the Nenets Autonomous Okrug.

ConocoPhillips has announced this week it going to sell all of its 19,21% stocks in Lukoil before 2011. The deal, which is believed to cost Lukoil about nine billion USD, would become one of the biggest transaction ever in Russia,  Vedomosti newspaper reports.

The US company has confirmed earlier this year it would sell 10 percent of the stocks. Now it is clear that it will get rid of the whole stake. ConocoPhillips has been owner of Lukoil's stake for five years.

In these years, the companies jointly have invested heavily in the Russia's Northwest. In the oil-rich Nenets Autonomous Okrug, the joint venture Naryanmarneftegaz has developed the huge Yuzhno Khilchuyu field with adjacent pipeline and port infrastructure. As BarentsObserver earlier reported, the field started production in fall 2008.