Johannesburg - Impala Platinum, the world's second-largest producer of the metal said on Thursday it would ask its striking South African employees to vote by text message this week on its latest wage offer and whether they wanted to return to work.

Spokesman Johan Theron said the vote would be conducted on Thursday or Friday and would involve striking miners who had indicated their willingness to take part.

The 15-week stoppage has also hurt rival producers Anglo American Platinum and Lonmin, hitting 40 percent of global production of the precious metal used for emissions-capping catalytic converters in automobiles.

Implats' move is the latest attempt by the three producers to undermine the Association of Mineworkers and Construction Union (Amcu) by taking a wage offer directly to miners after talks collapsed two weeks ago.

Implats said last week that two-thirds of its striking workers had already indicated by text message and phone calls that they wanted to return but it was now asking for a formal vote on the offer.

Lonmin has said that if enough of its miners indicate by Friday that they want to come back, it would aim to restart its operations next week.

The companies are offering increases of up to 10 percent that they say would raise the overall minimum pay package to 12,500 rand a month by July 2017, including cash allowances such as for housing.

AMCU had initially demanded an immediate increase to 12,500 rand in the basic wage, excluding allowances, but softened that stance in March to staggered increases that would amount to 12,500 rand within three or four years - still a third more than what the companies are offering as basic salaries. - Reuters