By Ed Stoddard
VENICE, Louisiana (Reuters) - BP <:BP.LO:>on Thursday cleared the way for an attempt to cap a runaway Gulf of Mexico oil spill and funnel crude to the surface in a high-stakes effort to slow a 45-day gusher.
The energy giant's undersea robots sheared off a pipe at the seabed site of the massive oil leak after more than two days of trying. Hours earlier, two rating agencies downgraded BP debt, reflecting assessments that the company would suffer lasting damage.
The U.S. disaster response chief, retired Coast Guard Admiral Thad Allen, said the next step, to begin later on Thursday, will be to position a containment cap over the riser pipe and attempt to bring at least some of the escaping oil and gas to the surface.
It was the first glimmer of hope for BP after many futile attempts to contain an oil leak that is belching 19,000 barrels of oil per day into the Gulf of Mexico. Allen called the day's developments a "significant step forward."
Ratings agencies Moody's and Fitch Ratings downgraded BP's credit ratings on Thursday and said they might cut them further on rising concerns about clean-up and legal costs.
Fitch, which in May admitted it had been wrong to assume that the impact of the spill on BP's finances would be eased by insurance, said clean-up costs could exceed its worst-case scenario of around $5 billion in any one year.
President Barack Obama, seeking to contain political fallout, planned to visit the Gulf coast again on Friday to view what has eclipsed the 1989 Exxon Valdez disaster as the worst oil spill in U.S. history.
The U.S. National Center for Atmospheric Research forecast that the oil slick would be driven by wind and currents around Florida by early summer and up the East Coast, possibly as far as North Carolina.
Shares in BP gained as much as 4.7 percent on Thursday as a call with analysts planned for Friday gave hope there would be an update on the company's plans for its dividend, which is seen to be threatened by the growing cost of the spill.
The shares later fell back to close in London up 0.58 percent on the day.
Investors were unimpressed with the progress made on capping the leak and shares of companies most closely related to the environmental disaster fell in U.S. trading. BP shares traded in the United States fell 0.3 percent, while shares of Halliburton Co. were down 2.2 percent and Cameron International dropped 1.87 percent.
SUSPEND DIVIDEND
Two U.S. lawmakers have called on BP to suspend any plans to pay out shareholder dividends until the full costs of the oil spill cleanup are calculated.
"We believe BP will bow to political pressure in the U.S. and suspend dividend payments for the remainder of 2010," said a research note from London-based investment bank Evolution Securities.
Oil has been gushing into the Gulf since April 20 when a Transocean Ltd drilling rig Deepwater Horizon licensed to BP exploded killing 11 workers. It threatens the fragile ecology and economies of Gulf coast states and put heavy pressure on the Obama administration to resolve the crisis.
Obama, whose reputation is on the line over the spill, scheduled his third visit to the Gulf on Friday.
The president's handling of the crisis has received skepticism from Americans and criticism from some U.S. commentators.
Washington Post columnist David Broder wrote on Thursday that Obama "will have to hope he doesn't end up as Jimmy Carter," the U.S. president who lost his 1980 re-election bid over his handling of the 444-day Iranian hostage crisis.
"We're going to get this thing closed, whatever it takes," Environmental Protection Administrator Carol Browner told National Public Radio.
The oil sheen loomed 6 miles off the north Florida coast and was expected to reach the white sandy shore there during the weekend.
EYE ON CURRENTS
Emergency planners kept a wary eye on two powerful currents in the Gulf, the loop ring that circles the bulk of the spill and the loop current that would carry oil south toward the Florida Keys and then up around the U.S. Eastern seaboard. They were expected to converge in 48 to 72 hours.
"Once those connect, that's it," state meteorologist Amy Godsey said.
Louisiana is the state hardest hit so far by oil, though the spill has fouled beaches in Mississippi and Alabama and now poses a threat to the Florida panhandle.
Thousands of fishermen, shrimpers and other seafood workers have been idled for weeks by government-imposed fishing restrictions that cover 37 percent of U.S. federal waters in the Gulf.
BP could face billions of dollars in fines and penalties if a Justice Department investigation finds wrongdoing, in addition to billions from the economic liability and damages, according to legal experts.
It may also find it more difficult to meet targets for expanded production in the future, analysts said.
(Additional reporting by Verna Gates on Dauphin Island and Michael Peltier in Tallahassee, Florida and Deborah Zabarenko in Washington)
(Writing by Steve Holland; editing by Alan Elsner)