As part of the changes taking effect from July 1,Mr Neilson's portfolio management responsibilities will be divided between Mr Clifford and portfolio manager Clay Smolinski.

The announcement has over-shadowed Platinum's half-year net profit of $104.6 million,which was up 7 per cent on the earlier corresponding period.

Revenue is up 15 per cent with net fund inflows of $900 million.

Mr Neilson assured anxious investors that he would stay on as executive director full time.

He plans to mentor newer members of the investment team and help with finding new clients in Europe and the US.

And importantly for existing clients,he said he would continue to work on generating investment ideas and company research.

James Carlisle,research director at InvestSmart Group,said it was a good profit result for Platinum.

"But we will be looking very closely at the funds under management numbers over the coming months to see if the stepping back of Mr Neilson will affect fund flows,"Mr Carlisle said.

"It funds under management keeps going up and there are no signs of anyone heading for the exits,then the share price should recover,"he said.