Wyser-Pratte Eurovalue, a $500m activist fund, suspended withdrawals on Tuesday.

Guy Wyser-Pratte, the veteran New York arbitrageur and activist said he was blocking withdrawals to protect investors. "Who could think of a more calamitous environment and a more opportune time to do something like this to protect non- redeeming shareholders and prevent redeeming shareholders shooting themselves in the foot?", Mr Wyser-Pratte added.

Activist funds are particularly hard hit by the current environment, with many down by 20 per cent or more for the year.

Mr Wyser-Pratte would not confirm rumours that the fund has lost 18 per cent since the end of June.