BP Plc took a $5 billion hit in its second quarter results on Tuesday, equal to more than three months of typical profits.
It is mainly down to a drop in the value of its assets but also includes extra money put aside for the 2010 U.S. Gulf oil spill clean up, the cost of which now totals $38 billion.
Other factors include the declining value of refineries the company has for sale in the US, a slump in the price of shale gas and the suspension of BP's Liberty project in Alaska.
It has tipped BP into a loss for the quarter of $1.385 billion with profits below expectations at $3.685 billion.
The results come as the company's management struggle to reach an end to litigation over the Gulf oil spill and in the middle of a row with its partners in Russia.