Crude oil in New York jumped to a record $64 a barrel as a threat to the American Embassy in Saudi Arabia heightened concern that supplies from the country, the world’s largest exporter, could be jeopardized.

The American Embassy in Riyadh and consulates in Jeddah and Dhahran will be shut through tomorrow because of a threat against American government buildings. The closings follow King Fahd’s death on August 1, which increased speculation about the stability of output from the region. Gasoline futures touched a record amid a series of refinery shutdowns.

“We’re worried about a disruption to supplies,” a senior vice president of energy trading at Advest Incorporated, Don Morton, said. “There’s a moment of weakness here with the Saudi changing of the guard. This could present itself as an opportunity to challenge the Saudi political structure,” he said.

Oil for September delivery surged $1.63, or 2.6%, to close at a record $63.94 a barrel on the New York Mercantile Exchange. Yesterday’s intraday high of $64 was the highest since the contract debuted in 1983. Prices are up 45% from one year ago.

King Fahd’s successor, Crown Prince Abdullah, has been in charge of day-today affairs since the king suffered a stroke in 1995. The country holds about 25% of the world’s proved oil reserves.

Adjusted for inflation, oil was more expensive during the 1970s.

Prices rose from 1979 through 1981 after Iran cut oil exports. The average cost of oil used by American refiners was $35.24 a barrel in 1981, according to the Energy Department, or $75.44 in today’s dollars.

In London, September Brent crude oil futures gained $1.63, or 2.7%, to close at a record $62.70 a barrel on the International Petroleum Exchange. Futures touched an all-time high of $62.76. Brent trading began in 1988.

Last month, the U.S. Embassy warned its citizens in Saudi Arabia of a possible terrorist attack in the kingdom.

At least 27 Westerners, 15 of them American citizens, have died in bomb and gun attacks since May 2003, when 12 suicide bombers struck residential complexes in Riyadh where foreigners live.

“There’s nothing that keeps us from going to $65,” a Paris-based senior energy analyst for Societe Generale SA, Deborah White, said.

“There are too many things going wrong for people to be short,” Ms. White said, citing the terrorist threats, Saudi succession, refinery outages, and the hurricane season in the Atlantic Basin. Shorts are bets that prices will fall.

Hedge-fund managers and other large speculators more than doubled their net-long position in New York oil futures in the week ended August 2, according to U.S. Commodity Futures Trading Commission data released on August 5. Longs are bets that prices will rise.

Retail gasoline prices also surged to a record. Crude oil accounts for about half the cost of a gallon of retail gasoline.