Willis and Towers Watson today announcing that they have merged and the value of the deal is expected to hit $18bn.

Willis shareholders will own approximately 50.1% of what will be Willis Towers Watson.

Willis chief executive Dominic Casserley said: “These are two companies with world-class brands and shared values.

”Together we will help our clients achieve superior performance through effective risk, people and financial management. We will advise over 80% of the world’s top-1000 companies, as well as having a significant presence with mid-market and smaller employers around the world.”

This is Willis’ second big deal of the year – the broker bought Miller Insurance Services in January.

Towers Watson chairman and chief executive John Haley said: “This is a tremendous combination of two highly compatible companies with complementary strategic priorities, product and service offerings, and geographies that we expect to deliver significant value for both sets of shareholders.”

Towers Watson has also been through significant change over the past few years with JLT acquiring its reinsurance brokerage business in September 2013 and rebranding as JLT Towers Re before dropping the ‘Towers’ in 2014.