BP shares plunge as U.S. probes oil spill

HOUSTON/WASHINGTON (Reuters) - British energy giant BP Plc's stock price plunged on Wednesday as it faced more U.S. government and congressional scrutiny over its handling of the Gulf of Mexico oil spill, the worst in U.S. history.

BP depositary shares trading in New York fell 9 percent, after closing down 4 percent in London, on worries the company will have to suspend its dividend payment under pressure from U.S. politicians who say it should go towards paying for legal claims and environmental damage in the Gulf.

"People are resigning themselves to the fact that there may be a suspension of the dividend," said Tony Shepard, an oil analyst at brokerage Charles Stanley in London.

Forty percent of BP's investors are in the United States, so any dividend cut would hit many Americans, although the company's importance to the broader market is less there.

U.S. Interior Secretary Ken Salazar told a Senate hearing he would ask BP to repay the salaries of any workers laid off due to the six-month moratorium on deepwater exploratory drilling imposed by the U.S. government after the spill.

Salazar said he would consider lifting the moratorium early if he received recommendations from a presidential commission investigating the spill sooner than expected.

The spill began on April 20 after an offshore oil rig explosion that killed 11 workers and ruptured the deep-sea well. It has caused environmental devastation along the U.S. Gulf Coast and threatens lucrative fishing and tourist industries. The spill also has presented a stern test of President Barack Obama's leadership.

Coast Guard Admiral Thad Allen, who is leading the government relief effort, told reporters that BP planned to move another rig to the spill site on June 14. This would enable the company to boost its capacity to collect oil from the well to 28,000 barrels (1.18 million gallons/4.45 million litres) a day, he said.

Allen did not indicate this meant the flow rate of the oil could be as high as 28,000 barrels a day, but his comments are likely to underscore that neither BP nor the government have yet managed to determine just how much oil is gushing out.

Government scientists have estimated that the leak spews 12,000-19,000 barrels a day, with one estimate as high as 25,000 barrels. They are due to present revised estimates later this week or early next week.

"I'm not going to declare victory or anything until I have hard numbers," Allen said.

In Washington, lawmakers and the Obama administration, which faces growing voter discontent over its handling of the crisis, kept up the pressure on BP and other oil companies.

BP America President Lamar McKay, along with top executives from Exxon Mobil Corp, Chevron Corp, ConocoPhillips and Shell Oil Co, were called to testify at a June 15 congressional hearing that will look at the oil spill and America's energy future.

BP's latest containment effort, which follows a series of earlier failed attempts, involved placing a containment cap with a seal on a deep-sea pipe from which the oil is gushing.

The captured oil is being channelled to a containment vessel on the surface above, where it is stored for later processing at a refinery ashore. Allen said the vessel was nearly full and was offloading its oil to a tanker.

The containment cap system is BP's most successful effort so far to deal with the leak, but large amounts of oil continue to spew into the ocean. Government scientists had warned that the latest effort could increase the amount of oil flowing from the well by up to 20 percent.

Salazar offered a lower figure at Wednesday's Senate hearing. "The rate of increase may have been somewhere between 4 and 5 percent over what it was before," he said.

(Additional reporting by Deborah Zabarenko, Ayesha Rascoe and Ross Colvin in Washington, Joanne Frearson, Harpreet Bhal and Natalie Harrison in London, Pascal Fletcher in Miami, Ernest Scheyder in New York and Kristin Hays in Houston; writing by Pascal Fletcher and Ross Colvin; editing by Will Dunham)