At its peak the syndicate, 210, which has ceased to trade, had 6,661 members. Only 2,560 now participate after a flood of departures in the wake of the losses.
Sturge made its disclosures following new rules made by Lloyd's which require agents to put forward syndicate results earlier for solvency purposes.
James Macdonald, group finance director, said the losses on 210 were caused partly by the rejection by underwriting members of Lloyd's pounds 900m rescue plan intended to relieve their losses.
Rejection of the plan caused other underwriters to increase their reserves, and this led to a rush of claims by members to claim on their stop-loss policies. Syndicate 210 and other Sturge syndicates have large exposures on personal stop- loss insurance.
Although 18 of Sturge's syndicates are not trading and show significant losses, 10 of the 13 still trading have shown a profit for the 1991 account, the latest completed trading period.