Crude-oil futures fell to the lowest level in five months on the New York Mercantile Exchange. On the Comex in New York, silver for September delivery fell as much as 6.2 percent, and copper futures dropped to a one-month low.
Commodities slumped, erasing gains for the year, on growing concern that the global economic recovery is faltering.
The Thomson Reuters/Jefferies CRB Index of 19 raw materials slumped 2.4 percent to 329.31 as of 1 p.m. in New York, led by declines in silver, energy and nickel. A settlement at that level would leave the index down 1 percent for the year.