Mabbutt helped launch Thames River in 1998 and helped build assets under its credit team to $3 billion by the end of 2007, when he stepped down from the business.
He had been best known for his management of the Thames River High Income and Thames River Hillside Apex funds. Since stepping back from full-time management Mabbutt has consulted for a range of clients, including Liontrust.
John Ions (pictured), Liontrust chief executive, said: ‘Michael is an excellent addition to our already strong fund management capability.
‘He has a long, proven track record of delivering strong performance for the investors in the funds that he has managed and sees the opportunity in the current economic and market environment to continue that at Liontrust.
‘Michael's appointment diversifies our offering away from our focus on equities into global credit, enabling us to further deepen and expand our distribution capability in the UK and internationally.’
Subject to regulatory approval, the business is expected to launch a global strategic bond fund in January.
'The global credit and currency markets appear to be distorted by, amongst other things, central bank intervention,' said Mabbutt.
'A moderation, or reversal, of such intervention one day might affect different areas of these markets in different ways. A global strategic bond fund that has the flexibility to invest across all areas of the global credit and currency markets should be an advantage.'