Prices for copper, zinc and aluminum have plummeted in the last four months as the global economic downturn cut demand from China and other developing countries who needed metals and steel to build up their infrastructure.

Mining companies who were hot last year and earning unprecedented profits until last September, have had to scramble to deal with the lower outlook by cutting costs, laying off workers, idling plants and reducing production.

In addition to the price fall, there are commodity supply shortages and dwindling reserves, while steel producers have idled blast furnaces as demand for their products, especially from the automobile industry, has dwindled.

The investor interest during the years of higher prices spurred a wave of consolidation, with some of the world’s biggest mining companies looking to acquire each other. But now those are on hold until signs the econony will turn.

The only positive has been for gold miners, who have seen the precious metal burst through the $1,000-per-ounce barrier as investors look for a safe haven in the economic turmoil.

Reuters has invited key players to talk at the Reuters Global Mining Summit March 9-11. The Summit will generate a series of exclusive interviews and articles from our team of expert reporters, as well as regular blog postings and online video.