A majority of the shares of Hermes, the investment firm which has a particular focus on ethical and sustainable investments, have been sold to US firm Federated Investors.
Hermes was previously owned by the BT Pension Scheme (BTPS). The pension scheme will retain a minority stake in the business, and remain a client of the firm.
Hermes management will own 10.5 per cent of the shares in the firm.
Under the terms of the transaction, Federated Investments will pay £246m to the BT Pension Scheme for a 60 per cent share of Hermes Investments.
The transaction is expected to be completed in the second half of 2018, and is subject to regulatory approval.
Hermes has assets under management of £33bn.
Hermes chief executive Saker Nusseibeh said Hermes and Federated Investors have complementary strengths.