* Copper at 3-month low, platinum at weakest in more than 2 months
* Firmer dollar also weighing, euro hits one-month trough
* Coming Up: U.S. New York Fed Empire State Survey; 1230 GMT
By Manolo Serapio Jr
SINGAPORE, April 16 (Reuters) - Commodities slid on Monday, with copper hitting fresh three-month lows and oil and grains also in the red, as worries about the global economy from China to Europe pushed investors out of risky assets.
Gold, otherwise a safe haven, fell too, as the dollar strengthened with rising Spanish bond yields renewing fears about the debt-plagued euro zone, and platinum sank to its lowest since January.
Worries about Spain, China's slowest first-quarter economic expansion in nearly three years and growing doubts about a U.S. economic recovery have combined to fuel aversion to risk assets.
"There's not much optimism out there. We think the second quarter should be the low point of this cycle as far as economic growth is concerned," said Jeremy Friesen, commodity strategist at Societe Generale.
Investors may be stepping back from markets, waiting for central banks from the United States, Europe and even China to boost their economies through more policy stimulus, he said.
Market players shrugged off China's weekend move to let the yuan trade more freely against the dollar, which economists say suggests Beijing is optimistic the economy is strong enough to withstand currency movements.
That vote of confidence, however, was not enough to allay the pessimism fueled by Friday's data showing that China, the world's No. 2 economy, grew an annual 8.1 percent in the first quarter, less than the 8.3 percent economists were looking for.
"The weaker than expected Chinese data appears to be the key driver of the market right now," said Tetsu Emori, a Tokyo-based commodities fund manager at Astmax Investments.
Three-month copper on the London Metal Exchange fell nearly 1 percent to a three-month low of $7,915 a tonne, adding to a 2.8-percent slide on Friday.
By 0334 GMT, LME copper was down 0.7 percent at $7,931.50, taking its Shanghai counterpart with it. Benchmark Shanghai copper fell as low as 56,700 yuan, its weakest since Jan. 11.
Front-month Brent crude slipped $1.38 to $119.83 a barrel. U.S. oil dropped 73 cents to $102.10.
Spot gold fell half a percent to $1,650.49 an ounce, pressured by a stronger dollar. Platinum dropped 1.6 percent to $1,569.45, after falling to $1,559 earlier, a level not seen since Jan. 25.
The dollar rose to its highest in a month versus the euro as Spain's soaring bond yields rekindled worries about the fragile state of the euro zone's economy, sending Asian shares lower too.
Spain's government bond yields rose and the cost of insuring its debt hit an all-time high on Friday, as record borrowing by its banks from the European Central Bank highlighted fears about the country's finances before it tests market appetite for its debt on Thursday.
In the grains markets, Chicago corn and wheat fell more than 1 percent to their lowest in two weeks and weather concerns eased as rains boosted the prospects for the U.S. crop.
Chicago Board of Trade May corn lost 1.3 percent to $6.21-1/4 a bushel, while May wheat fell by the same degree to $6.15-1/2, both at their lowest levels since March 30. (Additional reporting by Jessica Jaganathan; Editing by Clarence Fernandez)