Iron-ore swaps for November gained as Chinese traders bought the contracts to protect themselves against price increases in the cost of the commodity used to make steel.

The derivatives traded at about $117.75 a dry metric ton as of 10:41 a.m. in London compared with $117.5 a ton yesterday, according to data from SSY Futures Ltd., a broker of the contracts. Prices are gaining as Chinese mills restock and because of a lack of immediate, or prompt cargoes, Mark Richardson, head SSY Futures, said by e-mail.

The physical price of iron ore at the Chinese port of Tianjin has gained 37 percent to $118.70 a ton since Sept. 5, according to data from The Steel Index.

To contact the reporter on this story: Alaric Nightingale in London at anightingal1@bloomberg.net

To contact the editor responsible for this story: Alaric Nightingale at anightingal1@bloomberg.net