Mori was formed in 1969 by Sir Robert Worcester and specialises in social, corporate, specialist and field and telephone research. It is most renowned for conducting for the last three General Election exit polls for ITV News.
In the newly merged company, Ipsos UK chief executive Richard Sillman will become executive chairman of Ipsos Mori. Brian Gosschalk, chief executive of Mori, will be chief executive of Ipsos Mori, responsible for all client areas of the business, except media and operations.
Mori life president Worcester will take on a new role as chairman of the advisory board of Ipsos Public Affairs Worldwide.
Gosschalk said both companies have strong momentum, and the combination will solve the needs of Mori's evolving client base.
"The private sector side of our business will benefit from Ipsos' strong global network and the merged business will have a powerful public affairs and special research offering. With their independent heritages the two businesses also enjoy a good cultural fit."
Ipsos was founded in 1975 and is the third-largest survey-based reserach company globally with revenues of £418m last year.
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