Global oil prices rebounded on Wednesday over concerns about supply factors in Iran and Libya. Brent North Sea crude for December jumped $US1.30 to $US107.11 a barrel in late afternoon London deals. New York's main contract, West Texas Intermediate (WTI) for delivery in December, jumped $US1.24 to $US94.28 per barrel. Silver sank to a three-month low amid worries that economic reforms in China could sap demand for the industrial metal. Silver for December delivery, the most active contract, on Wednesday fell 33.6 cents, or 1.6 per cent, to settle at $US20.442 a troy ounce on the Comex division of the New York Mercantile Exchange. Silver futures came under pressure, mirroring steep losses in copper, as investors continued to sift through China's broad outline of economic policy, released on Tuesday, for clues about specific reforms. Gold futures gave up earlier gains in the final few minutes of trading as losses in silver weighed on its sister metal. Gold for December delivery, the most active contract, fell $US2.80, or 0.2 per cent, to settle at $US1,268.40 a troy ounce. Copper settled at its lowest price in over three months one the London Metal Exchange (LME) as concerns over China's growth and the longevity of US economic stimulus sent investors heading for the exits. LME three-month copper on Wednesday was changing hands for $US6,980 a metric ton at the close of open outcry trading - down two per cent on the day and its lowest daily settlement since August 5. Aluminium closed 0.3 per cent lower at $US1,794.50 a ton. Copper prices began sliding on Tuesday after China's Third Plenum -- a four-day meeting that set the course for the world's second-largest economy for the next 10 years -- failed to provide clear direction on policy over the coming decade. The statement that followed the meeting called for fewer investment restrictions and greater rights for farmers but was lacking in specifics.