Byline: PERRINE FAYE

LONDON, Nov. 27 (AFP) a" World oil prices rallied this week as temperatures dropped in the United States and western Europe, sparking demand for heating fuel.

Gold prices closed in on $500 per ounce for the first time in 18 years while aluminium struck the

The weekas trading ended on Wednesday in the United States owing to the Thanksgiving holiday. Consequently London saw shortened trading hours on Thursday and Friday.

The Commodities Research Bureauas index of 17 commodities rose to 314.80 points on Friday from 312.40 points the previous week.

Gold prices rose to almost $500 this week, a level last seen in late 1987, on strong buying by investment funds amid creeping inflation in the United States.

In London on Friday, prices reached $497.05 per ounce, the best value since December of that year.

"In the marketas current condition, $500 now looks within easy reach although a test of the psychological level might be the catalyst for hefty profit-taking," said James Moore, an analyst for the specialist website TheBullionDesk.com.

Gold is seen as a safe haven against high inflation.

On the London Bullion Market, gold prices jumped to $495.90 per ounce at the late fixing on Friday from $485.85 the previous week.

Silver prices extended gains above $8.0 in the wake of goldas rally.

Silver hit $8.23 per ounce on Tuesday, the highest level since April 4, 2004.

"The bullish tone in the base and precious complexes looks set to propel silver higher in the coming sessions," Moore said.

In addition to being key in jewellery manufacturing, silver is widely used by industry, particularly by the photographic and dental sectors.

On the London Bullion Market, silver prices rose to $8.20 per ounce at the late fixing Friday from $8.11 the previous week.

Palladium prices reached the highest level for one and a half years, before succumbing to profit-taking, while platinum steadied below $1,000 per ounce.

Palladium hit $268 per ounce on Monday, a value last achieved in April 2004. The metal is profiting from forecasts of shrinking supplies.

Palladium "could face some near term pressure given its recent impressive moves a" up almost 20 percent since the beginning of this month," Barclays Capital analyst Yingxi Yu said.

Platinum prices climbed after racing to the highest point in almost 26 years the previous week on strong speculative buying.

Platinum prices jumped by 7.0 percent in two weeks to reach $994 per ounce on November 17.

"For now consolidation within the $965-85 area remains the theme although with gold building for a test of $500 another push (by platinum) towards $1000 could be on the cards," Moore said.

On the London Platinum and Palladium Market, platinum climbed to $987 per ounce at the late fixing Friday, from 979 dollars the previous week.

Copper eased after touching a historic high of $4,224 per tonne on November 18.

"Although it looks like prices may well head higher still, the whole metals complex looks increasingly vulnerable," said William Adams, an analyst at specialist website BaseMetals.com.

The London Metal Exchange (LME) was meanwhile monitoring Chinaas potential copper trading scandal as part of its normal work, but has not held talks with Chinese authorities over the issue, the organisationas chief said Tuesday.

LME chief executive Simon Heale denied there had been any contact between the LME and the Chinese government amid mounting speculation that Beijing is desperately trying to stem losses from bad trades that could costs hundreds of millions of dollars.