LONDON (AFP) - Oil and gold prices extended their recent rallies this week as investors scooped up commodities on signs of a pick-up in a global economy that has suffered its worst downturn in decades. OIL: Oil prices jumped to six-month highs above 62 dollars a barrel in New York this week, lifted by rising stock markets, a sliding dollar and news of falling energy inventories in the United States, dealers said. As the week drew to a close, attention switched to a meeting of the OPEC cartel to take place on Thursday. New York crude reached 62.26 dollars on Wednesday the highest level since mid-November after data showed a fall in oil inventories in the United States, the worlds biggest energy-consuming country. US crude reserves tumbled 2.1 million barrels in the week ending May 15, far more than market expectations for a drop of 700,000 barrels. The bullish (positive) sign is that weve seen two consecutive weeks of falling inventories in the US, Tony Nunan, an energy risk manager at Mitsubishi Corp, said on Friday. Oil also won support from a weak greenback which makes dollar-priced crude cheaper for buyers holding stronger currencies and therefore tends to stimulate demand for the commodity. The euro on Friday rose above 1.40 dollars for the first time since the start of the year owing to concerns about high US debt, dealers said. In afternoon London trade, the European single currency hit 1.4005 dollars the highest level since January 2. The dollars decline has accelerated since Thursday after speculation increased that the US could potentially face a credit rating downgrade, said Lee Hardman, currency analyst at The Bank of Tokyo-Mitsubishi UFJ in London. While there was no specific news about the US sovereign rating, a warning by Standard & Poors on Thursday of a possible downgrade of Britains rating prompted fears the United States might be next, dealers said. Next Thursday meanwhile, OPEC holds a meeting in Vienna to discuss whether to alter the amount of crude the cartel is pumping. The Organization of Petroleum Exporting Countries, which produces some 40 percent of global supply, has steadily cut output since late last year in a bid to steady prices which have tumbled from record highs above 147 dollars a barrel reached last July. Libyas envoy to OPEC, Shukri Ghanem, told AFP on Thursday that the meetings outcome remained uncertain as member nations had yet to indicate a clear stance. Everyone has not made up their minds. They are just watching carefully the movements in the market, the different signals, he said. By Friday, on the New York Mercantile Exchange (NYMEX), light sweet crude for delivery in July stood at 60.93 dollars a barrel compared to 58.35 dollars for the expired June contract a week earlier. On Londons InterContinental Exchange (ICE), Brent North Sea crude for July jumped to 60.08 dollars a barrel from 58.07 dollars a week earlier. PRECIOUS METALS: Gold prices reached the highest point in almost two months, benefiting from its safe-haven status amid a weak dollar. Gold reached 961.33 dollars an ounce a level last seen on March 26. Prices rose across the board... with gold and silver being the strongest performers, said analysts at Barclays Capital. Gold prices have reverted to tracking currency movements in recent sessions... as the dollar weakened to its lowest level since the start of the year against the euro amid fresh concerns of credit downgrading. Meanwhile a report by industry body the World Gold Council said investment funds drove demand growth of the metal during the first quarter. By late Friday on the London Bullion Market, gold rallied to 959.75 dollars an ounce from 929.50 dollars a week earlier. Silver grew to 14.83 dollars an ounce from 13.92 dollars. On the London Platinum and Palladium Market, platinum climbed to 1,149 dollars an ounce at the late fixing on Friday from 1,109 dollars. Palladium gained to 234 dollars an ounce from 224.50 dollars. BASE METALS: Base metals prices diverged. Any gains for base metals resulted from another sharp drop in the dollar and continued declines in stockpiles, said MF Global analyst Edward Meir. By Friday on the London Metal Exchange, copper for delivery in three months rose to 4,582 dollars a tonne from 4,352 dollars a week earlier. Three-month aluminium fell to 1,437 dollars a tonne from 1,515 dollars. Three-month lead climbed to 1,425 dollars a tonne from 1,420 dollars. Three-month tin grew to 13,750 dollars a tonne from 13,595 dollars. Three-month zinc dipped to 1,492 dollars a tonne from 1,498 dollars. Three-month nickel increased to 12,642 dollars a tonne from 12,250 dollars. COCOA: Cocoa prices advanced in London and New York. Providing some support was a report of an outbreak of black pod disease in Cameroon, which will potentially cut mid-crop growth forecasts up to 20 percent, said analysts at Barclays Capital. While not a significant production loss in terms of the global market balance, such an announcement will have helped marginally refocus market attention onto the cocoa markets troubled supply side. By Friday on LIFFE, Londons futures exchange, the price of cocoa for delivery in July rose to 1,616 pounds a tonne from 1,607 pounds a week earlier. On the New York Board of Trade (NYBOT), the July cocoa contract increased to 2,432 dollars a tonne from 2,335 dollars. COFFEE: Coffee prices extended recent gains. New York (futures) continued to rally with the help of the weaker dollar and tightness of Arabica-quality coffee, said Sucden analyst Ryan Benett. By Friday on LIFFE, Robusta for delivery in July climbed to 1,526 dollars a tonne from 1,500 dollars a week earlier. On the NYBOT, Arabica for July jumped to 138.2 US cents a pound from 127 cents. GRAINS AND SOYA: Grains and soya prices climbed. Allendale analyst Joe Victor said it had been an ideal week for prices, with crude oil higher, (the) dollar lower and support of the stock market. Maize is used to make ethanol, a cheaper alternative to petrol used to power cars and that is refined from crude oil. By Friday on the Chicago Board of Trade, maize for delivery in July rose to 4.29 dollars a bushel from 4.17 dollars a week earlier. July-dated soyabean meal used in animal feed increased to 11.73 dollars from 11.30 dollars. Wheat for July advanced to 6.07 dollars a bushel from 5.77 dollars. SUGAR: Sugar prices gained and are set to rise further after Indias crop failure. Sugar prices are up 30 percent since the start of the year in the wake of a poor Indian harvest that has dented supplies after years of overproduction. We do believe the risk of prices moving higher is significant, said Toby Cohen, analyst at Czarnikow Group. New York sugar prices had struck a near three-year high of 16.06 cents a pound last week. The drastic underperformance of the 2008/09 Indian harvest alongside those in several other northern hemisphere locations has laid the way for a global (sugar) deficit of historic proportion, thus offering a seemingly irrefutable fundamental case for strong price performance, according to Barclays Capital analyst Nicholas Snowdon. By Friday on LIFFE, the price of a tonne of white sugar for delivery in August increased to 440.30 pounds from 435 pounds a week earlier. On NYBOT, the price of unrefined sugar for July gained to 15.62 US cents a pound from 15.45 cents. RUBBER: Malaysian rubber prices dropped in quiet trade. On Friday, the Malaysian Rubber Boards benchmark SMR20 fell to 160.10 US cents a kilogramme from 160.75 cents a week earlier.