BP said Tuesday its profit fell to $13.4 billion (£8.2 billion) last year, down from $17.1 billion in 2012.
The company said “lost income from asset sales, weaker margins on refining and higher exploration write-offs were to blame,” according to the BBC.
For the final three months of 2013, profit fell to $2.8 billion from $3.9 billion.
Including the impact of the asset sales and one-off gains, BP said, profit for the year more than doubled to $23.7 billion compared with $11.4 billion in 2012.
That includes a one-time gain from BP’s $17 billion sale of its interest in the joint venture TNK-BP, which it sold to Russia’s Rosneft.
BP has sold $38 billion in assets since the Deepwater Horizon disaster in the Gulf of Mexico,including $22 billion in 2013.
The disaster in 2010 killed 11 men and caused the biggest oil spill in U.S. history.
The company said the provision to cover the spill’s clean-up, fines, compensation and legal costs had now risen to $42.7 billion from $42.5 billion last year.
BP pleaded guilty in 2012 and paid $5.26 billion to resolve criminal and civil charges brought by the federal government.
It still faces potential fines under the Clean Water Act of $18 billion or more if the government proves gross negligence led to the spill of 4.2 million barrels of crude.
BP is arguing for fines of about $2.7 billion.
The company said the asset sales would result in lower production in 2014.
In October, BP announced it will sell a further $10 billion worth of assets by the end of next year.