Aon is planning an aggressive push in the mid-commercial market, according to sources.

Sources close to the company said that Aon was looking to acquire regional brokers in a bid to boost its share of medium-sized commercial business, a sector dominated by super regional brokers such as Smart and Cook, and Oval.

Aon commercial division chief executive David Martin said: "Our primary focus is to grow our mid-market share organically. The acquisition of regional brokers is not an immediate aim for us, though we will continue to review the situation through 2005 and 2006."

Martin recently outlined plans to increase Aon's share of the UK commercial lines market from 10% to 25% over the next three to five years.

At the time, he said high prices for brokers would prevent Aon from making acquisitions until at least 2005.

Such a strategy would put the broker into competition for acquisitions with other large brokers.

Marsh has embarked on a major acquisition drive in the regions beginning with the acquisition of Rochester Kemp earlier this year.

Willis, too, is believed to be on the hunt for regional brokers following its acquisition of Irish broker Coyle Hamilton in June.

In May, Willis was linked with Cumbrian broker Jeffries Group, a member of the Willis Commercial Network. Sources said that while the deal fell through, Willis remained on the lookout for acquisitions.