The company has made a deal to sell a 25 per cent stake in OM Asset Management to HNA Capital US for about £355m.

Old Mutual stated it will use the proceeds for “general corporate purposes”.

Following the transaction, Old Mutual's shareholding will reduce from 50.8% to 25.9%.

Bruce Hemphill, group chief executive of Old Mutual, said: "We are very pleased to announce this transaction which brings forward further realisation of value for Old Mutual. It represents another step in delivering our managed separation strategy and secures a strategic long-term investor for OMAM".

James Ritchie, chairman of OMAM's board of directors, said: "We are pleased to welcome HNA Capital US as a new, supportive investor in OMAM. We remain focused on executing our growth strategy, which includes working collaboratively with our high quality Affiliates to diversify their businesses and expand their global distribution opportunities, as well as acquiring new Affiliates, to generate strong, long-term value for all of our shareholders.

“We look forward to working with HNA Capital US to accelerate our growth strategy for the benefit of our clients, Affiliates and shareholders."

Guang Yang, chief executive of HNA Capital US, said: "OMAM is a diversified, at-scale multi-boutique asset management franchise with an attractive portfolio of high quality investment managers. We are pleased with our investment in OMAM and look forward to supporting OMAM's continued growth."

OMAM is a global, multi-boutique asset management company with approximately $240 billion of assets under management as at 31 December 2016.

The completion of the first tranche is subject to antitrust clearance under the Hart-Scott-Rodino Act in the US and is expected to take place in approximately 30 days.