Brit's Syndicate 250 made a loss equal to nearly a third of its capacity in the 2000 year of account.
Its result for the year was a loss of 28.4% of its capacity, which was £50.3m. Brit owned 28.4% of the capacity.
The result was a marked deterioration against a forecast loss in the range of 17.5% to 22.5%. This was due to reserve strengthening in its US financial institutions account, Brit said.
Syndicate 800 lost 22.2% on a capacity of £62.4m, 47% of which was owned by Brit.
Syndicate 735 lost 11.3% on a capacity of £85m, of which 48.7% was owned by Brit. Syndicate 1202 made a profit of 11.6% on a capacity of £51.5m.