In its latest World Economic Outlook, the IMF has forecast the global economy would shrink by 1.3% in 2009 ? the weakest performance by far in the entire post-World War II period ? while Australia?s economy would shrink 1.4% this year.

To the mining sector and the world?s largest miner BHP Billiton closed the day 3% higher at $A32.48.

Rival Rio Tinto surged to an intraday high of $58.74, up almost 9%, after a report on the *Age* website noted that Rio?s new chairman Jan du Plessis caught up with BHP chairman Don Argus following Rio?s annual general meeting in Sydney on Monday.

Rio cooled in afternoon trade to close the session at $58.60, up 6%.

On the London Metal Exchange overnight, three-month copper rebounded 0.7% to $US4540 per tonne, nickel gained 0.2% to $11,525/t while zinc fell 0.3% to $1470/t.

Spot gold gained 0.2% to $890.90 an ounce at 4:17pm AEST. Newcrest Mining gained 1.7% to close at $A28.89, Lihir Gold added 1.8% to $2.89 while Sino Gold fell 1.5% to $5.16.

Newcrest Mining today reported a 5% on-quarter drop in third quarter gold output as a result of production declines from the Gosowong and Cadia Valley operations.

The company also maintained full-year production guidance at 1.63-1.70 million ounces of gold and 85,000-88,000 tonnes of copper.

Paladin Energy closed today?s session 8.4% higher at $4.39. The uranium miner said it would reduce its annual production guidance on the back of project development delays at its Langer Heinrich and Kayelekera uranium projects.

Paladin said it was now likely to produce 3.0-3.1 million pounds of uranium oxide in the year to June 30, down from previous guidance of 3.5Mlb.

Fortescue Metals Group ended the session 2% higher at $2.62, OZ Minerals gained 1.6% to 63c, while Aquarius Platinum added 4.4% to $5.28.

A big mover by percentage on the bourse today was uranium play Deep Yellow which jumped 12.5c, or 81%, to close the session at 28c after announcing the discovery of substantial uranium mineralisation at depth at the INCA project in Namibia.