* Gold extends losses on falling oil, hits 2-week low
* Platinum drops 3 percent on fears of falling demand (Recasts, adds quotes)
By Lewa Pardomuan
SINGAPORE, Sept 2 (Reuters) - Gold struck a two-week low on Tuesday as speculators ditched some holdings after oil fell to its weakest in nearly five months and the U.S. dollar rallied to an 10-month high against a basket of currencies.
A political crisis in Thailand, Asia's fourth-largest gold investor, had yet to spur safe-haven buying and jewellery makers which had earlier bought gold on dips also disappeared.
Platinum dropped 3 percent to a one-week low on demand concerns.
Gold <XAU=> fell to $805.20/806.40 an ounce from $817.15/818.75 an ounce late in London. New York markets were closed on Monday for the Labor Day holiday.
"After breaking below $820, most people think it's a matter of time before gold retests $800," said Ronald Leung, director of Lee Cheong Gold Dealers in Hong Kong.
"The physical buyers are around but they pulled back a little bit when they saw the market going down. They are also watching how the dollar and oil prices behave," he said.
Oil <CLc1> sank almost $3 a barrel on Tuesday to its lowest since mid-April, extending the osses on initial signs that a weakened Hurricane Gustav spared major Gulf oil facilities. [
]The dollar index, a gauge of its performance against six major currencies, climbed 0.8 percent to a high of 77.881, breaking chart resistance at 77.85.
"The movements in oil prices and the U.S. dollar have both conspired against gold," said David Moore, an analyst at Commonwealth Bank of Australia in Sydney.
Gold has lost more than 20 percent in value since spiking to all-time high of $1,030.80 in March, mainly driven by profit taking, oil's falls from record highs and a rebounding dollar.
In the physical sector, buying from jewellery makers in Hong Kong subsided, while the market in Singapore was quiet with no signs of buying from investors in Thailand, where Prime Minister Samak Sundaravej declared a state of emergency. [
]Spot platinum <XPT=> dropped to $1,398.00/1,418.00 an ounce from $1,439.00/1,451.00 late in London on concerns about demand for autocatalysts due to poor car sales and a slowing U.S. economy. Prices hit a record high of $2,290 in March.
"Japanese sales of automobiles in August were below 200,000 cars, so it's very bad figure. The platinum price is under pressure. It's a very bearish factor," said Kazuhiko Saito of Interes Capital Management in Tokyo.
Saito pegged platinum's downside target at $1,350 an ounce - a level last seen in late August.
Automobile sales in Japan, excluding 660cc minivehicles, tumbled 14.9 percent in August year-on-year to 193,902 vehicles. Sales for August fell short of 200,000 vehicles for the first time in 37 years. [
]Autocatalysts, used to clean exhaust fumes, account for more than 50 percent of global platinum demand.
The benchmark platinum contract on the Tokyo Commodity Exchange, August 2009 <JPLc6>, fell 156 yen per gram to 4,829 yen. New York gold futures <GCZ8> lost $26.1 an ounce to $809.10.
Spot palladium <XPD=> fell to $288.50/296.50 an ounce from $297.00/305.00 an ounce. Silver <XAG=> dipped to $13.05/13.11 an ounce from $13.40/13.46 an ounce late in London. Precious metals prices at 0741 GMT Metal Last Change Pct chg YTD pct chg Turnover Spot Gold 805.40 -11.70 -1.43 -3.28 Spot Silver 13.08 -0.33 -2.46 -11.44 Spot Platinum 1398.00 -41.00 -2.85 -8.03 Spot Palladium 286.00 -12.00 -4.03 -22.28 TOCOM Gold 2818.00 -85.00 -2.93 -7.91 58721 TOCOM Platinum 4830.00 -155.00 -3.11 -9.53 25818 TOCOM Silver 456.30 -21.80 -4.56 -15.66 941 TOCOM Palladium 1018.00 -62.00 -5.74 -24.65 805 Euro/Dollar 1.4534 Dollar/Yen 108.20 TOCOM prices in yen per gram, except TOCOM silver which is priced in yen per 10 grams. Spot prices in $ per ounce. (Editing by Nick Trevethan)