Energy giant BP said today that annual profits almost halved as the effect of lower oil prices took its toll.

The UK company said its full-year surplus was $13.96 billion in the year to December 31 - down 45% on 2008. Oil prices slumped in 2009 from their peak of $147 a barrel during the previous year.

Profits for the final quarter rose 33% to $3.45 billion, but this was below City forecasts.

BP said the lack of a significant hurricane season helped 'very strong' production last year - with a particularly mild season in the Gulf of Mexico meaning relatively few disruptions to oil and gas production.

As a result it expects 2010 to be at a lower level, but the firm said its long-term production guidance was unchanged.

Production grew by 4% in 2009 and the average across several years is still expected to be around 1%-2%.

The oil firm has seen a steep reduction in profits from its downstream refining business - where weak demand has hammered margins. Profits for the full year were $743m, compared with $4.18 billion in 2008.

BP chief executive Tony Hayward is in the process of a turnaround strategy for the firm, which has lagged rival Royal Dutch Shell in the past.

The company reduced staff numbers by 3,000 in 2008 with another 5,000 jobs shed last year, amid estimated cost savings of $4 billion.

It sold off assets last year, including divesting its interests in the Tengiz oil field in Kazakhstan and the pipeline which carries oil to Russia by selling its 46% stake in LukArco to Russia's Lukoil for $1.6 billion.