Norwich Union (NU) and AXA are set to increase commercial lines rates by as much as 10% from 1 November.

The rises will apply across a broad range of commercial classes, including property and fleet, and could signify the beginning of a hard market.

AXA said it would be introducing rate increases of between 5% and 10% to guard against more significant hikes in the future.

NU said it would increase rates by an average of 5% across many of its commercial lines.

NU director of trading Janice Deakin said further increases would follow. “This is not a flash in the pan. Concerted rate increases will follow in 2008.”

The move follows the insurers’ declaration in August that they would be increasing commercial rates in the wake of the summer floods. At the time they were reluctant to map out a specific timetable.

Allianz is also looking to raise commercial rates. Chris Hanks, Allianz commercial general manager, said the insurer was in discussions with brokers to test their reaction.

He said: “An increase of between 5% and 7% is the target – but it depends on the reaction we get from our brokers.

“If we get the opportunity, we will do it.”

Hanks said Allianz had already increased fleet rates by 3% in September.

He added that further rate hikes of between 6% and10% could be expected across the market by the end of next year.

But other insurers, including Zurich, have said they have no immediate plans to apply flat-rate increases across their commercial lines books.

Royal & SunAlliance would not comment on rate movement.