Shares of copper mining companies fell Wednesday on sinking prices for copper and other metals.
The price of copper, which tends to track investors' outlook for global growth, fell 12 cents, or 3.6 percent, to $3.19 a pound by early afternoon Wednesday. That's its lowest level since October 2011.
Worries about an economic slowdown in China, one of the world's largest consumer of raw materials, triggered a drop in prices Monday for oil, copper and other commodities. Gold prices have also been sliding since last week, taking a toll on the price of silver and other precious metals.
Lower metal prices can cut into miners' revenue.
In other bad news for the industry, a massive landslide last week halted operations at a major U.S. copper mine owned by Kennecott Utah Copper. Kennecott is a subsidiary of international mining conglomerate Rio Tinto PLC, whose U.S.-traded shares dropped $2.33, or 5.1 percent, to $43.33 in afternoon trading Wednesday.
Freeport-McMoran Copper & Gold Inc., which is the world's largest publicly traded copper mining firm, is expected to report its first-quarter results on Thursday. Its shares sank $1.56, or 5.3 percent, to $27.69 Wednesday.
Stifel analyst Paul Massoud lowered his price target on the company's stock to $45 from $47 Wednesday because of falling gold prices. He kept his long-term copper price estimate at $2.50 a pound.
Southern Copper Corp. shares sank $1.49, or 4.5 percent, to $31.31.