Oil major BP beat expectations for the fourth quarter of 2014 thanks to a surprise profit from its stake in Russian oil giant Rosneft while taking a $3.6 billion impairment charge and cutting spending due to low oil prices.

The firm reported underlying replacement cost profit at $2.2 billion versus expectations of $1.5 billion. BP's stock jumped over 5 percent at the opening, outperforming the broader European oil and gas sector.

The outperformance was due to an unexpected profit of $470 million from Rosneft which has been hit hard by Western sanctions over Moscow's role in Ukraine as well as the falling oil prices.

BP, which holds a 19.75 percent stake in Rosneft, said the figures were based on provisional numbers and could change.

BP's profit from the Rosneft stake, lower than the $1.1 billion profit reported a year earlier, was due to a change in the Russia firm's foreign exchange accounting system, BP officials said.

The profit from Rosneft offset a 42 percent decline in profits from oil production, known as upstream.

BP also said it took a $3.6 billion post-tax net charge, or a $7.4 billion pre-tax charge, mainly relating to impairments of upstream assets in the North Sea and Angola due to lower oil prices. That resulted in a fourth quarter replacement cost loss of $969 million.

The company said it would cut capex to $20 billion in 2015 from $22.9 billion in 2014. It maintained its quarterly dividend at 10 cents per ordinary share.

"We have now entered a new and challenging phase of low oil prices through the near and medium term," said Bob Dudley, BP's chief executive. "Our focus must now be on resetting BP."

BP's peers, including Chevron and Royal Dutch Shell, have responded to the drop in oil prices by around 60 percent since June by cutting spending over the next few years.

Shell said it would trim its planned investments by $15 billion over the next three years but warned against "overreacting" to the declines. Chevron executives slashed the company's 2015 capital budget by 13 percent to $35 billion.

BP has sold $40 billion of assets since the 2010 Gulf of Mexico spill and announced an additional $10 billion of disposals by the end of this year.

BP said production for full year 2015 is expected to be higher than 2014 despite plans to reduce exploration expenditure and postpone marginal projects.

BP's net debt at the end of 2014 was $22.6 billion and the debt-to-capitalization ratio 16.7 percent, slightly above the 16.2 percent ratio a year earlier.