Precious metals rose sharply early Tuesday in New York as traders returned from the last long weekend of the summer in a buying mood, shrugging off weaker crude oil prices and a mixed dollar.

Though floor traders were still trying to get their bearings after Monday's U.S. Labor Day holiday, there was some speculation that metals were benefiting as investors grew more sour on crude oil after recent declines in the price.

"I'm thinking there is some money coming out of the energies and coming into metals," said a floor broker. "We saw some fund buying earlier last week. We continue to see a little bit of buying here this morning."

Silver took a leading role overnight, but gold sprinted ahead at the open on the COMEX division of the New York Mercantile Exchange.

December gold at 9:38 a.m. EDT (1338 GMT), was up $12.10, or 1.9 percent, at $644.70 an ounce, trading to a 25-day high at $646.50 from $631.60, the bottom overnight.

Another broker said the floor considered $649 an ounce the next resistance point for the benchmark contract.

Spot gold fetched $636.00/80, up from $624.85/625.85 an ounce when trading wrapped up Friday afternoon. Tuesday's morning fix in London was $629.75.

"It is quite a sharp jump when you consider oil is well entrenched below $70 and the U.S. dollar at $1.28 against euro is relatively strong," said Bernard Hunter, a director of precious metals trading at ScotiaMocatta in Toronto. "Gold's reaction is probably breaking away from those traditional indicators."

hough the dollar was firmer at $1.2810/12 per euro, it was off against the yen, which makes gold a cheaper buy for Japanese investors.

December silver was up 24 cents at $13.31, trading from $13.0350 to $13.37, its highest price since May 30.

"The summer holidays are over," noted Hunter. "People are now laying in positions for the remainder of the year."

Silver has outperformed gold in recent weeks, rising about 39 percent in value since mid-June. Gold has climbed around 16 percent in the same period.

Traders cited positive technical factors for silver compared with gold and good demand for a silver exchange-traded fund that launched on the American Stock Exchange in late April, said analysts.

One of the brokers said he expected December silver to reach $13.50 by the end of the week.

Spot silver climbed to $13.14/13.21 from $12.89/12.96 an ounce late Friday. Bullion dealers fixed Tuesday's spot reference rate at $13.15.

In platinum, NYMEX October futures were up $23.10 at $1,277.90 an ounce. Spot platinum was quoted at $1,264/1,268.

December palladium was up $4.40 at $349.60 an ounce. Spot was quoted at $348/353.