By Adrian Croft and Kristen Hays
KABUL/HOUSTON (Reuters) - Prime Minister David Cameron offered to help deal with BP Plc's Gulf of Mexico oil spill on Thursday, saying he would take it up with U.S. President Barack Obama, as the beleaguered company's shares rebounded from 14-year lows.
It was the first time that Cameron had spoken publicly about the crisis. Cameron, who took office in May and is under growing pressure domestically to stand up for the British company, is due to talk to Obama by telephone at the weekend.
Obama has been sharply critical of BP and the two leaders' conversation will have to seek a delicate balance between domestic pressures and longstanding U.S.-British ties.
BP pleaded for patience from Americans frustrated at the spill, the worst in U.S. history and now in its 52nd day. But the Obama administration kept up the heat, saying it would make sure BP paid all damages and cleanup costs.
The spill has soiled 120 miles (190 km) of U.S. Gulf coastline and threatens multi-billion-dollar fishing and tourist industries.
BP was the second most active stock on the NYSE as the share rebounded by more than 8 percent by 1:45 p.m. ET (6:45 p.m. British time). It took a 16 percent dive to a 14-year-low on Wednesday amid concerns over BP's ability to meet mounting costs.
"The stock is obviously volatile as investors try to wager on the outcome of the Gulf oil spill," said Jud Pyle, chief investment strategist at Options News Network, a division of option market maker PEAK6 Investments in Chicago.
Analysts said the company's improved performance was partly due to speculation that PetroChina, Asia's top oil and gas firm, was considering making a bid for BP.
Shares in Anadarko Petroleum Corp and Transocean Ltd, two companies involved in the rig collapse, also jumped on Thursday. In London trading, BP stocks sank to their lowest level since 1997, before bouncing off their lows and closing 6.7 percent down.
Illustrating the extent of investor concerns about BP, the cost of insuring its AA-rated debt traded for a time at levels normally associated with "junk" status.
'GIVE US A CHANCE'
BP said it was capturing more oil from its deep-sea well in the Gulf of Mexico that ruptured on April 20 after an explosion on an oil rig on the surface that killed 11 workers. It is still not known though how much oil is gushing out.
BP's chief operating officer, Doug Suttles, said the company was doing everything it could to contain and clean up the spill.
"It's very difficult for people to believe that right now, and I know that, but I would just ask, just give us a chance," he told CNN."We've got to get this job done. We've got to get this well killed."
The Obama administration has markedly toughened its rhetoric towards the company in recent days, reflecting public anger over the oil giant's handling of the spill.
U.S. Attorney General Eric Holder said on Thursday the "American people will not pay a dime" for the clean-up of the Gulf region and pledged to hold BP financially responsible.
A senior Democratic politician joined calls from U.S. lawmakers for BP to suspend dividend payments. Asked if BP should do this, U.S. House of Representatives Speaker Nancy Pelosi said: "Yes of course, and that would be their best public relations instead of taking out all these ads."
CAMERON:UNDERSTANDS 'FRUSTRATION'
In Britain, business leaders urged the government to defend BP -- the biggest single payer of dividends among UK listed companies -- against U.S. threats to expand the company's liabilities for the spill and pressure from the United States for it to suspend payment of its quarterly dividend.
Cameron, speaking on a visit to Kabul, said, "This is an environmental catastrophe. BP needs to do everything it can to deal with the situation, and the UK government stands ready to help."
He added, "I completely understand the U.S. government's frustration. The most important thing is to try to mitigate the effects and get to grips with the problem. It's something I will discuss with the American president when we next talk."
Earlier on Thursday, a British government spokesman said Cameron would talk to Obama on the subject over the coming weekend in their first discussion since speaking when Cameron took office.
After Wednesday's battering in New York, BP had lost more than half its market value since the crisis began.
"BP notes the fall in its share price in U.S. trading last night. The company is not aware of any reason which justifies this share price movement," BP said in a statement on Thursday.
One of the world's largest corporate giants, BP said it had the financial flexibility to deal with liabilities related to the spill, which to date had cost it around $1.43 billion (973 million pounds).
Restructuring experts agree that by running the numbers alone, BP looks able to handle the financial damage.
CONTAINING THE SPILL
BP's latest containment effort, which follows a series of earlier failed attempts, involves placing a containment cap with a seal on a deep-sea pipe from which the oil is gushing into the Gulf of Mexico.
It said on Thursday the cap system had collected 15,800 barrels (660,000 gallons/2,500,000 litres) in the previous 24-hour period. The cumulative total since the system was installed last week has reached 73,324 barrels (3,080,000 gallons/11,660,000 litres), according to BP figures.
The spill has fouled wildlife refuges in Louisiana and barrier islands in Mississippi and Alabama. It has also sent tar balls ashore on beaches in Florida. One third of the Gulf's federal waters remains closed to fishing.
There were visible signs of anger in Louisiana, where the fishing ban is taking a heavy toll on the local economy.
At Maw's Sandwich and Snack Shop in Boothville, Louisiana, where french fries smothered in gravy are on the menu, a poster said, "Obama Needs A Lesson In Leadership And Compassion."
(Additional reporting by Alex Chambers in London, Matt Daily in New York, Ed Stoddard in Dallas, Jeremy Pelofsky in Washington and Anna Driver in Louisiana; writing by Ross Colvin; Editing by Will Dunham and Frances Kerry)
