World number two platinum industry leader Implats says it is considering whether to invest more money in its Zimbabwean Makwiro mine.

The firm says it may ramp up investment in the site with a $750 million outlay as it aims to enhance dramatically the level of pgm production.

CEO Keith Rumble told Business Day that the investment could come before spring, noting that the end of the first quarter - around March - represented a "realistic target" for starting work.

Mr Rumble said that Zimbabwe would ultimately account for 22 per cent of Implats' total production, a marked increase on the current level of seven per cent.

However, the Implats chief stressed that more work was necessary in tandem with the government, with the current lack of clarity over mining requirements and regulations causing unease in some quarters.

He said that the platinum miner would have to settle on fixed investment conditions with President Robert Mugabe and establish clear guidelines in particular on managing dollar-denominated costs and debt.