London ? If U.S.-led forces invade Iraq, world oil prices probably will plunge from current levels and stay there — so long as the conflict ends quickly and causes little damage to production capacity in the Persian Gulf, several energy analysts said Friday.

However, a war that spills into neighboring countries or one in which Saddam Hussein sabotages his own oil fields could panic markets and trigger a spike in prices to $50 or even $60 a barrel, some said.

The wide range of forecasts is a sign of the difficulty analysts face in trying to envision how markets will react to a war of unpredictable severity.

Fighting might be over in a few days, or it might erupt into a regional conflagration that affects crude exports from Kuwait and even Saudi Arabia. How OPEC and oil-importing countries respond to a war also will have a great influence on prices.

Perhaps the only certainty is that markets will welcome any move that keeps supplies flowing.

Crude prices fell Friday on reports that Saudi Arabia’s state-run oil company Saudi Aramco had chartered supertankers to carry an exceptionally large shipment of crude — 28 million barrels — to the United States for delivery in May.

Kuwaiti government official Abdullah Kubeshi collects a crude oil sample from an oil lake formed in 1991 after a retreating Iraqi army set nearly 900 oil wells on fire at Burgan Oil Field, just south of Kuwait City. Oil prices may rise to 0 a barrel during an extended war with Iraq, experts say.

Analysts say that fears of a wartime disruption in supply have swollen crude prices by at least $5 a barrel. This so-called war premium has increased along with tensions in the Persian Gulf because markets worry that hostilities with Iraq will paralyze that country’s 2 million barrels in daily oil shipments.

Although prices might rise in the last hours before any actual outbreak of hostilities, several analysts predicted that an attack on Iraq would knock the floor out from beneath the market — just as it did when coalition forces launched Operation Desert Storm on Jan. 16, 1991.

Futures contracts of U.S. light, sweet crude plummeted by $10.90 a barrel on Jan. 17, 1991, to close in New York at $21.30.

“History would suggest that oil prices would go down fairly rapidly, maybe $5-7 a barrel, probably within one day,” said Angus McPhail, an analyst at ING Financial Markets in Edinburgh, Scotland.

He believes that markets will be awash in crude after a swift war, particularly if Venezuela continues to recover from an oil industry strike and other members of the Organization of Petroleum Exporting Countries keep busting their output quotas. For the second half of the year, ING Financial Markets foresees an average Brent crude price of $18.50 a barrel.