Aon has announced that it will buy Willis Towers Watson (WTW), combining the world's second and third-largest insurance brokers to create an £80bn organisation.
The all-stock transaction will see Aon become the world's largest insurance broker, pushing Marsh & Mclennan into second place.
WTW shareholders will receive 1.08 Aon shares for each Willis share that they own, valuing WTW's equity at approximately $30bn (£22.9bn).
"This combination will create a more innovative platform capable of delivering better outcomes for all stakeholders, including clients, colleagues, partners and investors," said Aon CEO Greg Case.
"Our world-class expertise across risk, retirement and health will accelerate the creation of new solutions that more efficiently match capital with unmet client needs in high-growth areas like cyber, delegated investments, intellectual property, climate risk and health solutions."
Aon said that it expects $800m of pre-tax synergies by combining the two companies, generating more than $10bn in shareholder value creation.
Approximately 73% of the savings are expected from the consolidation of business and central support functions, including leveraging the capabilities of the Aon Business Services operational platform across the combined group; and
The rest of the savings are antcipated through the consolidation of infrastructure related to technology, real estate and third-party contracts.
Aon will maintain operating headquarters in London. John Haley will take on the role of executive chairman with a focus on growth and innovation strategy.
"The combination of WTW and Aon is a natural next step in our journey to better serve our clients in the areas of people, risk and capital," said WTW CEO John Haley.
"This transaction accelerates that journey by providing our combined teams the opportunity to drive innovation more quickly and deliver more value."
The transaction is subject to the approval of Aon Ireland and WTW shareholders, as well as other customary closing conditions, and is expected to close in the first half of 2021.