SINGAPORE, Aug 16 (Reuters) U.S. oil prices fell back below \$73 a barrel on Thursday, unwinding so

SINGAPORE, Aug 16 (Reuters) U.S. oil prices fell back below $73 a barrel on Thursday, unwinding some of the previous day's gains on signs a major storm brewing in the Atlantic might not endanger Gulf of Mexico oil platforms.

U.S. crude oil prices fell 52 cents to $72.81 a barrel by 0157 GMT, paring Wednesday's 95-cent gain, which had also been aided by a big decline in weekly U.S. crude stocks.

London Brent crude fell 56 cents to $71.08 a barrel after gaining $1.13 a day ago.

Tropical Storm Dean, expected to become a hurricane by the weekend, was first feared heading into the Gulf toward the middle of next week, but some recent computer models show it making landfall in about five days in Central America.

''The convergence (of forecasts) over the past 24 hours is for a more southerly path rather than into the thicket of oil and gas platforms in the Gulf of Mexico,'' said Tobin Gorey, a commodities strategist at Australia's Commonwealth Bank.

Tropical Storm Erin is a more immediate but less serious threat to oil facilities as it is expected to make landfall Thursday evening south of the refining hub at Corpus Christi, Texas, the U.S. National Hurricane Center said.

Forecasts said Erin, packing maximum winds of just 40 miles per hour (65 kph), could strengthen further before it comes ashore, but local officials said the greatest risk was of heavy rains and possible flooding.

Shell shut down a small natural gas production facility in the path of the storm on Tuesday and began evacuating nonessential personnel.

Other companies operating in the Gulf, home to a third of U.S. oil and gas production, were monitoring the situation.

Three oil refineries in Corpus Christi process over 800,000 barrels a day of oil.

Prices also rallied after government data showed U.S. crude stocks fell 5.2 million barrels last week, in part due to lower imports, more than double the forecast decline. However supplies remain well above seasonal norms.

Oil prices have rebounded from a more than one-month low last week, but analysts say they remain vulnerable to shock waves from the ongoing credit-related turmoil in other financial markets.

U.S. stock markets fell sharply on Wednesday, wiping out the year's gains as traders feared that the woes afflicting the U.S. subprime mortgage sector were spreading to other parts of the credit market, and could yet inflict wider economic damage.

N] Asian stock markets fell sharply on Thursday.

Oil markets suffered a first wave of subprime-related selling early this month, knocking prices from an Aug. 1 record high of $78.77 amid profit taking and liquidation to meet margin calls in other markets. But analysts say the greater risk is any sign of a faltering U.S. economy in the fallout from the turmoil.

''Ahead of last Thursday people were worried but not too worried. Now you're talking about a definite different view of the world,'' said Gorey. ''We got to $70 because demand is strong, but all of a sudden you have a genuine question about global demand.'' REUTERS SZ VP0758