Reuters

NEW ORLEANS - An oil and gas platform operated by Mariner Energy burst into flames in the Gulf of Mexico, but the crew of 13 escaped and there were no signs of an oil spill, the US Coast Guard said.

"The boats and the aircraft on scene cannot see a sheen," US Coast Guard Captain Peter Troedsson told a news conference in New Orleans.

Initially, Mariner reported there was a mile-long oily sheen on the water around the platform, according to the government.

The fire burned for several hours before it was extinguished.

A company spokesman said it started on an upper deck of the platform where living quarters were located, and had not been caused by a "blowout," or sudden release of oil and gas from a well.

The crew, plucked from the Gulf by an oil supply vessel, was transported to a hospital onshore and no injuries have been reported, the Houston-based company said.

Automated shutoff equipment turned off the flow of oil and gas from the platform's seven producing wells as the crew evacuated, Mariner said.

The cause of the fire is still unknown and under investigation, the company said.

"It's unlikely to have long-term implications for production in the Gulf of Mexico," senior director at PFC Energy in Houston Raoul LeBlanc said.

Nevertheless, the accident brought unwelcome attention to the offshore drilling industry as it is trying to roll back a six-month deepwater drilling moratorium imposed in the wake of the BP Plc Macondo well disaster, which killed 11 workers and poured 4.1 million barrels of oil into the Gulf.

Environmental groups said the Mariner explosion reinforced the need to keep the moratorium in place.

White House spokesman Robert Gibbs said he did not know whether the fire would affect the moratorium, scheduled to expire November 30.

Several analysts said the accident could hurt the industry in its court battle to lift the drilling halt early.

"The incident has happened at the wrong time," head of commodity research at Commerzbank Eugen Weinberg said.

"The political establishment will probably move quickly as everybody still remembers the slow dealing with the Macondo accident and the dramatic pictures from this summer."

The platform is located more than 145 kilometres south of Louisiana's Vermilion Bay, 200 miles west of BP's ruptured Macondo well. It is in relatively shallow water 104 meters deep.

The platform's output is a small fraction of the 1.6 million barrels of oil and 6.4 billion cubic feet of gas the region produces on a daily basis.

The facility averaged 9.2 million cubic feet of natural gas per day and 1,400 barrels of oil and condensate per day during the last week of August, Mariner said.

News of the fire helped push crude oil prices up $US1.11 to $US75.02 a barrel on the New York Mercantile Exchange. Oil prices were also boosted by Hurricane Earl, which is threatening refineries along the US East Coast.

Shares of Mariner Energy fell 2.6 per cent to close at $2US2.75 and shares of Apache Corp , which is expected to buy Mariner Energy in a $US2.7 billion deal, fell 1.3 per cent to close at $US91.30.

Apache plans to proceed with the Mariner purchase, Apache spokesman Bill Mintz, said.

Mariner has participated in at least 35 deepwater projects in the Gulf and operated over half of them.

The fire was the fifth reported at offshore sites operated by Mariner since October 2006, according to the US Bureau of Ocean Energy Management, Regulation and Enforcement.

None of the earlier fires caused any fatalities, although workers were injured in two of the accidents.

The company also suffered a blowout while drilling a well about 90 miles off the Louisiana coast in May 2008, but the well was brought under control within a few hours.