A one-off £9.4m accounting charge and a £7.2m investment loss helped push Amlin into a pre-tax loss of £18.2m for the first six months of 2000.

However, Amlin said it had achieved a technical £1.5m profit on its core underwriting operations, compared to a loss of £1.5m for the same period in 1999.

In a joint statement, Amlin chairman Roger Taylor and chief executive Charles Philipps, said: “The group's reported results belie the improvements in our core underwriting operations, where the incurred loss ratios on business incepting in 2000 are approximately 18% better that their 1999 equivalents.”

Most of Amlin's underwriting improvement was down to its Coles marine division, and Amlin Insurance Services, its motor fleet account.

But results for Amlin's non-marine business, Harvey Bowring, were described as “disappointing” by the insurer.

Amlin has decided to merge its three syndicates – 902, 1141 and 2001 – to become syndicate 2001, for that year of account. Syndicate 2001 will have its capacity increased by 6.9% to £575m, enabling Amlin to write an extra 15% of premium income.

Two extraordinary factors are said to have affected Amlin's interim results.

The first is a £16m drop in its investment income compared to last June, after the value of Amlin's share portfolio fell £7.2m.

However, the public limited company said it had since recouped most of this loss.

The second factor is a £9.4m charge made to Amlin's profit and loss account, for goodwill relating to the sale of its members' agency business.

Previously, the company would have been permitted to write off goodwill against its reserves but an accounting rule change prevented this.

Taylor and Philipps also announced that Amlin had acquired an additional £59.4m or 10.3% of managed syndicate capacity.

The result is that Amlin now owns 67.5% of its managed syndicate capacity and it expects to make further purchases during the remaining year 2000 capacity auctions.