The London Club has announced an increase of 25% in its advance call for the 2003/04 policy year.
In the same move, the Club confirmed that supplementary calls for open underwriting years will remain unchanged.
Paul Hinton, chief executive of the Club's manager A Bilbrough & Co, said: "The almost unprecedented failure in the last three years of the investment markets to produce budgeted returns means that a substantial upward correction of premium levels has been required.
"Considerable progress has already been made, but, in the context of continuing investment market uncertainty, more needs to be done.
"Any increase in the cost of the Club's share of the International Group's excess loss reinsurance programme, which has not yet been determined, will also apply. Advance and supplementary calls will continue to be levied in instalments on the same basis as applies in the current year."
