Oct. 24 (Bloomberg) -- The number of vessels hired to ship iron ore to China slid 61 percent last week as steel prices fell and stockpiles expanded, Commodore Research & Consultancy said.

Eleven shipments of iron ore, an ingredient in steel, were chartered to China last week, down 17 from the week before and 12 below the trailing four-week average, New York-based Commodore said in a report e-mailed today. Chinese steel prices fell 7 percent to 4,380 yuan ($686) a metric ton last week, the largest such drop since October 2009, and domestic steel stockpiles rose 2 percent to 15.1 million tons, it said.

“Going forward, Chinese steel production appears likely to come under additional pressure during at least the next few weeks,” Jeffrey Landsberg, Commodore’s managing director, said in the e-mail. “Chinese iron ore demand is likely to come under sporadic pressure.”

China’s demand for iron ore helped more than triple rents for capesize vessels, the largest ships that haul the raw material, since Aug. 1 to $30,975 a day, according to the Baltic Exchange, the London-based publisher of shipping rates on global maritime routes.