Aon has backed away from a possible offer for rival broker Willis Towers Watson after yesterday saying it was in the early stages of considering a deal.

“Aon today confirms that it does not intend to pursue this business combination,” the company said in an announcement to the US Securities and Exchange Commission.

The company says it regularly evaluates a variety of potential opportunities and had considered a possible action related to Willis Towers Watson, which is subject to Irish regulatory requirements.

“As a result of media speculation, those regulations required Aon to make the disclosure at a very early stage in the consideration of a potential all-share business combination,” it said.

Aon’s preliminary look at Willis Towers Watson follows Marsh & McLennan’s decision last year to launch a takeover for JLT in a $US5.6 billion ($7.9 billion) deal.

That transaction is expected to close in the northern spring, subject to regulatory approvals.

Aon’s New York-listed shares closed up 4.3% after it said it was not going ahead with a transaction. The stock rebounded from a 7.8% slump the previous day when it fell on news of a possible deal.

The company has more than 50,000 employees in 120 countries and a deal with Willis Towers Watson could have been the biggest merger in the global broking sector.