World gold prices are likely to average $645 a troy ounce in 2007, up $39 on year due to strong investment and fabrication demand amid a slowdown in supplies, an analyst said Thursday.

"Silver prices might appreciate to an average of $13.65/oz during the same period compared with $11.60 (last year), also because of investment demand," said Jeffrey M. Christian, managing director of CPM Group.

At 1020 GMT, the London AM gold fix was $660.50/oz.

CPM is a leading precious metals and commodities research consulting company based in the U.S.

Christian said global demand for gold for fabrication would grow to 79.6 million ounces in 2007, up 8.2% on year, while investment demand would be around 39.7 million ounces, down 8.7%.

"Though on a year-on-year basis, investment demand is declining, it's still much higher than the average over the last several years of 20 million ounces," he added.

He said supplies have stagnated as new mine additions are few and far between, while most major central banks have cut down on gold sales.

"In 2006, central banks sold 11 million ounces of gold, which is likely to come down to just 9 million ounces this year," he said.

On gold mine production, Christian said world output would be around 63.8 million ounces this year.