The South African mining firm, Impala Platinum Holdings (Implats), has confirmed that a deal to sell its stake in Lonplats, the platinum division of Lonmin, is still on track despite missing a deadline last week.

The $800 million transaction was announced by Implats last September and was due to be completed by February 27.

However, Implats chief financial officer, David Brown, told Reuters that the agreement to comply with South Africa's black empowerment regulations, was still being fine-tuned.

He stated: 'I can say there are no problems. Empowerment transactions of this size and complexity do take time, we are making good progress and hopefully we will be able to make some announcement in the short term.'

Under the terms of the deal, Implats, the second biggest platinum producer in the world, will sell 9.1 per cent (out of a total 27.1 per cent holding) of Lonplats back to Lonmin for $269 million.

The remaining 18 per cent stake will be sold to newly formed empowerment firm Inkwala for $531 million.

New legislation, due to come into force in May, compels mining firms to transfer 15 per cent of local mining assets to black ownership within five years, rising to 26 per cent within 10 years, in an attempt to boost black participation in the country's economy.