NEW ORLEANS (Commodity Online) : The massive oil spill in the Gulf of Mexico, leaking from a ruptured well moved closer to the mouth of the Mississippi River.

Analysts said the oil spill that threatened to eclipse even the Exxon Valdez disaster spread out of control with a faint sheen washing ashore along the Gulf Coast.

The spill was bigger than imagined ,five times more than first estimated ,and closer. Faint fingers of oily sheen were reaching the Mississippi River delta, lapping the Louisiana shoreline in long, thin lines, they said.

The oil slick could become America's worst environmental disaster in decades, threatening hundreds of species of fish, birds and other wildlife along the Gulf Coast, one of the world's richest seafood grounds, teeming with shrimp, oysters and other marine life. Thicker oil was in waters south and east of the Mississippi delta about five miles offshore.

The leak from the ocean floor proved to be far bigger than initially reported, contributing to a growing sense among many in Louisiana that the government failed them again, just as it did during Hurricane Katrina. President Barack Obama dispatched Cabinet officials to deal with the crisis.

It is pouring out crude oil at a rate of up to 5,000 barrels (210,000 gallons) a day, according to the National Oceanic and Atmospheric Administration - five times more oil than previously estimated.

The rising threat has deepened fears of severe damage to fisheries, wildlife refuges and tourism in Louisiana, Mississippi, Alabama and Florida.

US Coast Guard worked with BP, which operated the oil rig that exploded and sank last week, to deploy floating booms, skimmers and chemical dispersants, and set controlled fires to burn the oil off the water's surface.

The company has requested more resources from the Defense Department, especially underwater equipment that might be better than what is commercially available.

Government officials said the blown-out well 40 miles offshore is spewing five times as much oil into the water as originally estimated about 5,000 barrels, or 200,000 gallons, a day.

At that rate, the spill could eclipse the worst oil spill in U.S. history _ the 11 million gallons that leaked from the grounded tanker Exxon Valdez in Alaska's Prince William Sound in 1989 _ in the three months it could take to drill a relief well and plug the gushing well 5,000 feet underwater on the sea floor.

Ultimately, the spill could grow much larger than the Valdez because Gulf of Mexico wells tap deposits that hold many times more oil than a single tanker.

BP conducted a test burn on Wednesday, but abandoned a plan to set fire to more oil after weather conditions deteriorated. The attempt to burn some of the oil came after crews operating submersible robots failed to activate a shut-off device that would halt the flow.