LONDON (Bloomberg) — Shares of Griffin Mining Ltd. rose as much as 13 percent after the company announced plans to spend $7.1 million to expand its Caijiaying metals-processing plant in China.The expansion will increase annual capacity to 750,000 metric tons of ore in 2008 from 200,000 tons, Bermuda-based Griffin Mining said today in a statement.

The shares gained 7.75 pence, or 8.8 percent, to 96 pence in London. Earlier, they climbed as much as 11.25 pence to 99.5 pence, the highest since May 12.

The first part of the upgrade next year will allow the company to produce gold, silver and lead for sale in China, Griffin Mining said in the statement. Revenue will be increased "substantially" because of higher zinc output, the company said. Funding will come from the $33 million Griffin holds in cash.