CHICAGO, Aug. 16 (Xinhua) -- Gold futures on the COMEX Division of the New York Mercantile Exchange extended gains on Tuesday, as downbeat economic data from Europe weighed on sentiment, prompting investors to flock to safe-haven assets.

The most active gold contract for December delivery rallied 27 dollars, or 1.5 percent, to 1,785 dollars per ounce.

Eurostat announced Tuesday that the euro zone's gross domestic product climbed 0.2 percent in the second quarter compared with the preceding quarter, which is the slowest pace since 2009, and below expectations for 0.3 percent growth, adding to concerns that the European economy is at risk of slipping into a "double-dip" recession.

German Chancellor Angela Merkel and French President Nicolas Sarkozy announced proposals Tuesday to boost the governance of the euro zone and reaffirmed their commitment to defending the euro.

But some market analysts believed that the proposal failed to alleviate worries about the financial health of the euro zone, as it fell short of an action plan with concrete steps.

A trader mentioned that gold got a strong boost as many investors sought a safe place to park cash amid uncertainty about global economy.

Silver for September delivery jumped 51.2 cents, or 1.3 percent, to 39.819 dollars per ounce. Platinum for October delivery climbed 20.9 dollars, or 1.2 percent, to 1,818.1 dollars per ounce.