Shanghai: Copper imports by China, the biggest consumer, advanced to the highest level in 20 months in November as stronger local prices than in London prompted traders to increase buying.

Inbound shipments of the refined metal, copper alloy and products gained 18 per cent to 452,022 metric tonnes from 383,507 tons in October, according to Bloomberg calculations based on data posted on the website of the General Administration of Customs. That's the highest level since March 2010, according to Bloomberg data.

The sixth monthly gain will help fill a supply gap, after domestic production of the refined metal fell to a five-month low in November, and Shanghai Futures Exchange-monitored warehouse inventories dropped to a 28-month low at the beginning of December. Copper in London has fallen 19 per cent this year on concern the deepening debt crisis in Europe and slowing global economic growth will damp metals demand.

"This is a big amount, which explains why the high cash premiums seen at the end of November have disappeared," Xiao Jing, an analyst at Beijing Capital Futures Co said by phone on Saturday.