Cornhill's premium income increased by 14.4% in the first half of the year to Euros 1.4bn (£894m).
The result was pushed up by higher commercial property premiums and the strength of the UK motor market.
Cornhill's claims ratio fell to 71.3% from 73.2% despite several major claims in commercial property, according to parent company, Allianz.
Cornhill's expense ratio improved to 30% from 31.7%.
But falling investment income cancelled out the positive effect of the improvement in the combined ratio.
Earnings after tax came to Euros 34m (£21.7m), just down from the Euros 35m (£22.4m) recorded in the same period last year.
