Oil prices have fallen for the first time in five days on the eve of Federal Reserve chief Ben Bernanke's highly anticipated testimony to Congress on the outlook for the US economy. The market also awaited the US Department of Energy's weekly report on Wednesday on the nation's commercial petroleum reserves, whichhave hovered near record highs in recent weeks. New York's main contract, West Texas Intermediate light sweet crude for June, fell 55 cents to $US96.16 ($A98.35) a barrel on its last day of trade. Brent North Sea crude for delivery in July dropped 89 cents to $US103.91 a barrel in London trade. Bernanke will appear before Congress's Joint Economic Committee on Wednesday to give an update on the outlook for the world's biggest economy. Gold futures fell as traders moved to the sidelines ahead of US Federal Reserve Chairman Ben Bernanke's testimony to Congress. The most actively traded contract, for June delivery, on Tuesday fell $US6.50, or 0.5 per cent, to settle at $US1,377.60 a troy ounce on the Comex division of the New York Mercantile Exchange. Gold cut its earlier losses near midday Tuesday, briefly pushing toward unchanged after James Bullard, the president of the Federal Reserve Bank of St Louis, said in a speech that the central bank should press forward with its bond-buying program, but be willing to change its size depending on economic events. Gold also was pressured on Tuesday by another decline in the amount of gold held by exchange-traded funds. The ETFs' hoard fell by almost 10 metric tons Monday, to 2,142 tons, according to UBS. Copper prices closed slightly lower on the London Metal Exchange (LME) after an uneventful trading session that saw investors drift to the sidelines ahead of US Federal Reserve Chairman Ben Bernanke's address to Congress. At the PM kerb close on Tuesday, LME three-month copper was 0.3 per cent lower at $US7,365 a metric ton. Aluminum was flat at $US1,860 a ton.