Shares of mining companies fell Thursday on new signs of slower growth in China and Europe.
Investors are worried that weakening economies in China and Europe could affect worldwide demand for raw materials such as copper and coal.
A Chinese manufacturing index compiled by HSBC declined to 48.1 in March from 49.6 in February. Figures below 50 indicate that manufacturing is contracting. The report came on the heels of weaker Chinese housing data, adding to questions about the outlook for the world's second-largest economy. Fast growth there has been a key factor shoring up the global economy since the financial crisis of 2008.
China is a huge importer of raw materials that are used in everything from power generation to manufacturing and construction. If it produces fewer goods and cuts back on building as its economic growth slackens, that could hurt prices for coal, iron and other commodities.
Separately, financial information company Markit said that its European purchasing managers' index declined to 48.8 in March from 49.3 in February. The index tracks the services and manufacturing sectors for countries that use the euro as currency.
In addition, new government statistics showed that Ireland dropped back into recession at the end of 2011.
Gold and copper miners were down in midday trading: Shares of Freeport-McMoran Copper & Gold Inc. fell $1.51, or 3.8 percent, to $38.29; Barrick Gold Corp. shares fell 65 cents to $42.98; and shares of Newmont Mining Corp. dropped 72 cents to $52.45.
Coal miners, which supply material for power generation and making steel, also fell. Alpha Natural Resources Inc. dropped 74 cents, or 4.4 percent, to $15.97; Arch Coal Inc. declined 45 cents, or 3.7 percent, to $11.61; Cliffs Natural Resources Inc., which mines coal and iron, declined $2.45, or 3.5 percent, to $68.65; James River Coal Co. dropped 27 cents, or 4.5 percent, to $5.67; and Peabody Energy Corp. fell 97 cents, or 3 percent, to $30.49.