BEIJING/HANOI - A suspension of mining in Myanmar could lead to further tightening of global supplies of tin, China's Yunnan Tin, the world's top refined tin producer, said on Tuesday.

On Monday, Myanmar's ethnic minority Wa militia said that from August the Wa region - a key tin producer - would suspend all mining activities to protect the remaining resources after more than a decade of "disruptive and wasteful mining".

The news sent tin prices skyrocketing, with the most-traded May contract on the Shanghai Futures Exchange SSNcv1 up as much as 17.5% in two sessions and the benchmark three-month contract on the London Metal Exchange CMSN3 hitting a two-and-a-half month high.

"The company is closely monitoring the Chinese raw material supply," Yunnan Tin told Reuters in a statement, adding that it would make "timely adjustment to its operations" as the impact on supply hinged on the implementation of the suspension.

The International Tin Association (ITA) said in a report on its website that "it is still unclear how and if these plans will be implemented."

Myanmar accounted for 77% of China's tin ore imports last year, Chinese customs data showed. The Wa region is estimated to have accounted for over 70% of Myanmar's tin production in 2022, the ITA said.

The main tin mine in the self-declared Wa State, which borders China's Yunnan province, is Man Maw, which produced around 32 000 t of tin in 2020, the ITA said in a 2021 report.

"This tin is generally smelted in China and mining investment is thought to be sourced from China," the report said.

Less significant tonnages of tin are also mined in Myanmar government-administered areas including the Mawchi mine in Kayah State and the Heinda mine in the Tanintharyi Region of southern Myanmar, the ITA added.

Myanmar is estimated to have the world's third largest tin reserves at 700 000 t - or 15% of global reserves, behind Indonesia's 800,000 tonnes and China's 720 000 tonnes, US Geological Survey (USGS) data in 2023 showed.

Other major tin mining countries include Peru, Democratic Republic of Congo, Bolivia, Brazil and Australia.

Tin is used in the electronics and semiconductor industries.

Shares of Yunnan Tin hit their highest since June 2022 at 17.96 yuan ($2.61) on Tuesday. They jumped 10% in the previous session on the Myanmar news.

Yunnan Tin last year produced 77,100 tonnes of refined tin, around a fifth of global output, ITA data showed.

China is the world's biggest consumer of tin and is also the top producer of tin ore and refined tin. Four of the world's top 10 refined tin producers are Chinese, data by the ITA showed.