Gold gained for the third straight session in New York after North Korea said it detonated a nuclear bomb, spurring demand for a haven.

Gold is up 12 percent this year, partly as tensions over Iran's nuclear research program escalated. North Korea's test breaks an almost decade-long worldwide moratorium on nuclear testing.

``It's adding some support to gold,'' said Frank McGhee, head metals trader at Integrated Brokerage Services Inc. in Chicago. ``The amount of verification and the size of the bomb is still in question. It's not being taken as an earth-shattering event yet.''

Gold futures for December delivery rose $3.40, or 0.6 percent, to $580.2 an ounce at 10:06 a.m. on the Comex division of the New York Mercantile Exchange. The metal tumbled 4.5 percent last week.

A futures contract is an obligation to buy or sell a commodity at a set price for delivery by a specific date.

The U.S. is still analyzing the data and has not confirmed that the explosion detected was a nuclear device, White House Press Secretary Tony Snow said. Chinese officials first notified the U.S. of the test. North Korea said it detonated a bomb on Oct. 8.

Gold's gains may be limited because the conflict with North Korea may not threaten oil supplies, some analysts said.

``Gold tends to move higher on risk aversion only when oil supply is threatened,'' or when there are large bets the metal will fall, said John Reade, an analyst at UBS AG in London. ``Neither condition has been met by the events of the weekend.''

`Locked Up With Oil'

Some investors buy gold and precious metals when energy expenses climb. Gold futures reached a record $873 an ounce in January 1980, after Iran cut oil supplies, doubling crude costs in a year and sparking a surge in the inflation rate.

Oil and gold generally have moved in tandem. Crude oil rose today after members of Organization of Petroleum Exporting Countries said they would voluntarily cut production to stem a 23 percent slide in prices during the past two months.

``Gold and silver are still locked up with the oil market,'' McGhee said. ``Gold doesn't have a mind of its own.''

Gold is down 21 percent from a 26-year high of $732 an ounce in mid-May, partly as oil prices have declined. Silver futures for December rose 27.5 cents, or 2.5 percent, to $11.45 an ounce on Comex.

Hedge-fund managers and other large speculators decreased their net-long position in Comex gold futures in the week ended Oct. 3, U.S. Commodity Futures Trading Commission data showed

Speculative long positions, or bets prices will rise, outnumbered short positions by 69,434 contracts, the lowest since early August 2005, the data showed. Net-long positions fell by 1,810 contracts, or 2.5 percent, from a week earlier.