Picture: Boxer Ngwenya.

Johannesburg - Shares of South African platinum producers decline after members of the industry's main trade union voted overwhelmingly on Sunday to strike at Anglo American Platinum this week.

That followed recent votes to strike at Impala Platinum and Lonmin Plc.

A simultaneous strike at the three would hit over half of global output and further squeeze margins of the struggling companies.

Shares of Impala Platinum, the world's second-largest producer, drop 2 percent to 117.58 rand.

Top producer Anglo American Platinum declines 0.7 percent to 402.99 rand.

Johannesburg-listed shares of Lonmin Plc, the third-largest producer, shrug off the news and are up 0.8 percent at 56.75 rand. - Reuters