Ingenious Asset Management and Thurleigh Investment Managers have agreed to merge, said spokeswomen for the firms.
The deal already has received approval from the Financial Conduct Authority, and is expected to close on April 30.
The deal creates a £1.8 billion ($3 billion) money manager. Existing Thurleigh clients will continue to be run by Thurleigh, said its spokeswoman. New clients of the combined businesses will be run under the IAM brand.
IAM manages £1.5 billion of assets, largely in global multiasset portfolios, on behalf of pension funds and other investors. Thurleigh manages £300 million of on- and offshore assets for charities and other clients.
The firms will create a portfolio steering group to set the investment strategy. Guy Bowles, founder and CEO of IAM, will continue in his position at the new firm. David Rosier, chairman and co-founder of Thurleigh, will continue as chairman of Thurleigh. Charles MacKinnon, co-founder and chief investment officer of Thurleigh, will become part of the portfolio steering group at the new firm.