International financial services and insurance group Old Mutual has acquired US-based United Asset Management for around £1.5bn – £1bn in equity and £557m in debt.

UAM is one of the largest independent asset management organisations in the world with £139bn under management, and offers a wide range of investment management services.

The acquisition will increase Old Mutual's assets under management to around £196bn.

Around 93% of the common stock in UAM had been acquired by the end of the tender offer. The rest of the shares are likely to be purchased shortly, making UAM a wholly-owned subsidiary of Old Mutual.

Mike Levett, chairman of Old Mutual, said: “This enhances Old Mutual's position as a leading financial institution by substantially broadening and diversifying our geographic reach and business policies.”