The 20 smelters in Antaike's monthly tin production survey churned out 13,369 tonnes of the metal last month, with Yunnan Tin announcing the end of its 45-day smelter maintenance in mid-August.

The increase came despite southern Chinese provinces including tin heartland Yunnan restricting metal producers' electricity consumption due to a shortage of power supply and a drive to reduce carbon emissions.

A resumption of production at the Yinman tin mine in Inner Mongolia in mid-August will alleviate tight supply of raw material tin concentrate as output ramps up, Antaike said.

It sees September refined tin output rising slightly from August, even as an equipment and plant overhaul at China Tin may not be completed until mid-month and another smelter, Guangdong Hanhe, goes on maintenance.

(Reporting by Tom Daly; Editing by Jan Harvey)