Iron ore fell to the lowest level in almost three weeks on worries that a seasonal decline in demand from steel mills and slowing growth in China, which imports more of the ore than all other nations combined, will curb purchases.

The price of ore with 62 percent iron content delivered to the port of Tianjin declined 0.4 percent to $133.50 a dry ton on Monday, the lowest price since June 12, according to an index compiled by The Steel Index Ltd. Prices fell 2.5 percent last week, taking the second-quarter loss to 9.2 percent.

"The third quarter is known as the dead zone," Tom Price, an analyst at UBS AG, said by phone from Sydney.