Professional services firm Aon has abandoned its plan to acquire rival firm Willis Towers Watson within 24 hours after saying that a primary discussion is underway.

Quoting sources familiar with the development, Bloomberg has reported that Aon is preparing to submit a $24bn offer to acquire Willis Towers Watson.

Aon in a statement said: “Aon had considered such a possibility with regard to Willis Towers Watson. News of that consideration subsequently became public and Aon was required to issue a statement because Willis Towers Watson is an Irish company and 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. Aon today confirms that it does not intend to pursue this business combination.”

“As a result of this announcement, Aon is bound by the restrictions set out in Rule 2.8 of the Irish Takeover Rules. Aon reserves the right within the next 12 months to set aside this announcement where so permitted under Rule 2.8 (including Rule 2.8(c) (ii)).”

Had the deal materialised, Aon would have emerged as one of the largest brokers by revenue in the world, overtaking Marsh & McLennan.

Willis Towers was established in 2016 after Willis Group acquired the consultancy Towers Watson & Co for around $8.9bn.