LONDON — BP's costs arising from the devastating oil spill in the Gulf of Mexico have rocketed to 3.12 billion dollars (2.49 billion euros), the company revealed on Monday.

"The cost of the response to date amounts to approximately 3.12 billion dollars, including the cost of the spill response, containment, relief well drilling, grants to the Gulf states, claims paid, and federal costs," it said in a statement.

The group added: "It is too early to quantify other potential costs and liabilities associated with the incident."

The latest estimate of costs, equivalent to 2.06 billion pounds, is far higher than the 2.65 billion dollars that was given one week ago.

The company's share price has collapsed by more than 50 percent since the Deepwater Horizon oil rig which the company operated sank on April 22, two days after a blast killed 11 workers.

After intense pressure from President Barack Obama over the worst ever US environmental disaster, BP agreed on June 16 to suspend its shareholder dividend and create a 20-billion-dollar fund for costs arising from the spill.

BP is also selling non-core assets to raise 10 billion dollars, while international ratings agencies have downgraded the company's credit worthiness.

Meanwhile, efforts to clean up the spill gathered steam Monday after Hurricane Alex prompted a five-day shutdown.

Clean-up workers arrived back on Grand Isle, Louisiana by the hundreds, spilling off school buses that shuttled them in from around the state.

In the wake of Hurricane Alex, beaches, shorelines and marshes lay smeared with thick patches of oil and the sky was still filled with ominous, gray clouds.

Skimming resumed in Louisiana but high seas kept vessels tied up in harbor in three other southeastern US states and no controlled burns were being carried out.

Operations were suspended last week as Tropical Storm Alex, which later became the first Atlantic hurricane of the 2010 season, entered the Gulf.