LONDON (AFP) - Oil prices stormed to record highs this week, spiking above 135 dollars as investors showed no let-up in their thirst for black gold amid tight supplies, high demand and a weak dollar. OIL: Brent North Sea oil struck an all-time high of 135.14 dollars and New York light sweet crude reached a record 135.09 dollars on Thursday, driven by growing concerns that energy supplies will fail to keep up with demand. They later slumped as investors banked profits but resumed their upwards march on Friday. "It seems there is no stopping soaring oil prices," said Andrey Kryuchenkov at the Sucden brokerage in London. "Investors doubt that the market will be able to meet ever growing demand in the long run, with booming emerging market economies underpinning robust demand for energy." Crude futures have risen by more than a third since the beginning of 2008 when they struck 100 dollars for the first time, lifted by unrest in oil-producing countries, falling energy inventories, OPEC's unwillingness to hike output, high Asian demand for fuel and a weak dollar. A struggling US currency makes dollar-commodities cheaper for foreign buyers. Oil prices breached 130 dollars for the first time on Wednesday and continued higher on news that US energy inventories had unexpectedly fallen last week. PRECIOUS METALS: Gold shone, reaching a near five-week high. Soaring oil prices raised concerns about inflation, encouraging investors to buy gold, which is widely regarded as a good store of value. Silver benefited from the rise of gold, while platinum was also boosted by lingering supply disruptions in key exporter South Africa. On the London Bullion Market, gold gained to 927.50 dollars per ounce at Friday's late fixing from 897 dollars a week earlier. Silver advanced to 18.10 dollars per ounce from 16.83 dollars. On the London Platinum and Palladium Market, platinum increased to 2,182 dollars per ounce at the late fixing on Friday from 2,136 dollars a week earlier. Palladium jumped to 451 dollars per ounce from 443 dollars. BASE METALS: Base metals prices slumped, with nickel and zinc hitting two-year lows. "With (mining) strikes and disruptions taking a back seat, and with high oil prices threatening the global economy, it may well be that supply concerns will start to diminish and be overtaken by concerns over the prospects for falling demand," said William Adams of By Friday, copper for delivery in three months fell to 8,200 dollars per tonne on the London Metal Exchange from 8,296 dollars a week earlier. Three-month aluminium dropped to 2,988 dollars per tonne from 3,010 dollars. Three-month nickel slid to 23,510 dollars per tonne from 26,305 dollars. Three-month lead dropped to 2,020 dollars per tonne from 2,276 dollars. Three-month zinc declined to 2,143 dollars per tonne from 2,318 dollars. Three-month tin slumped to 23,700 dollars per tonne from 25,300 dollars. COCOA: Cocoa prices extended losses, hitting a five-week low in London. Major producer Ivory Coast said Thursday that considerably less of its home-grown cocoa beans were being smuggled and sold in nearby non-producing countries. By Friday on LIFFE, London's futures exchange, the price of cocoa for July delivery slid to 1,377 pounds per tonne from 1,458 pounds a week earlier. On the New York Board of Trade (NYBOT), the July cocoa contract fell to 2,573 dollars per tonne from 2,665 dollars. COFFEE: Coffee prices rose strongly at the start of the week but went off the boil towards the end as speculators took profits. By Friday on LIFFE, Robusta for July delivery declined to 2,248 dollars per tonne from 2,265 dollars a week earlier. On the NYBOT, Arabica for July delivery fell to 134.60 US cents per pound from 137.90 cents. SUGAR: Sugar prices extended their downward spiral. "Sugar faltered to a three-week low ... as plentiful supplies weighed on the market," wrote analysts at Barclays Capital. By Friday on LIFFE, the price per tonne of white sugar for August delivery fell to 326 pounds from 331.10 pounds the previous week. On NYBOT, the price of unrefined sugar for July delivery declined to 10.24 US cents per pound from 11.10 cents. GRAINS AND SOYA: Grains and soya prices were mixed as markets tracked the path taken by oil. Maize and soya are used to produce ethanol, which is a cheaper alternative to gasoline (petrol). Brazil is a major producer and consumer of ethanol used to power vehicles. By Friday on the Chicago Board of Trade, maize for July delivery climbed to 6.01 dollars per bushel from 5.91 dollars the previous week. July-dated soyabean meal used in animal feed dropped to 13.61 dollars from 13.78 dollars. Wheat for July delivery fell to 7.49 dollars per bushel from 7.75 dollars. RUBBER: Rubber prices extended their rally, boosted by record-high oil prices and as heavy rain in Asian producing countries disrupted output. "Supply is expected to recover this month," said one dealer. Owing to soaring oil prices, buyers are switching to natural rubber from synthetic. On Friday, the Malaysian Rubber Board's benchmark SMR20 rose to 302.70 US cents per kilo from 288.90 a week earlier.