Jan. 15 (Bloomberg) -- Gold rose for a sixth straight day on increased investor demand for an alternative to the slumping U.S. dollar. Platinum, palladium and silver also gained.

Investment in the StreetTracks Gold Trust, the world's biggest exchange-traded fund, or ETF, backed by gold, increased 10.75 metric tons yesterday to a record 652.56 tons, according to the World Gold Council. Gold has climbed 8.6 percent this year as the dollar dropped 1.7 percent against the euro.

``People are buying the ETF because they don't know what else to buy,'' said Adrien Biondi, global head of precious metals at Commerzbank AG in Luxembourg. ``It's a hedge against the dollar mainly and the outlook for the U.S. economy is not very good.''

Gold for immediate delivery rose $1.47 to $905.60 an ounce as of 9:24 a.m. in London, bringing the increase over the past six days to 5.5 percent. The price yesterday rose to a record $914.30.

Gold futures for February delivery rose $3, or 0.3 percent, to $906.40 an ounce in electronic trading on the Comex division of the New York Mercantile Exchange.

Silver for immediate delivery advanced 2.63 cents to $16.4113 an ounce. Platinum increased $1 to $1,578 and palladium gained $1.25 to $379.75.

Following are technical gauges for gold:

20-day moving average              849
100-day moving average             780
200-day moving average             732

14-day relative strength index     77.66

Fibonacci        Start    End      50%       38.2%
                 745      914      830       810

To contact the reporter on this story: Claudia Carpenter in London at ccarpenter2@bloomberg.net or ccarpenter2@bloomberg.net.

Last Updated: January 15, 2008 04:48 EST