Based in London, Webster joins after 12 years at Aberdeen Asset Management, the last decade of which he spent as senior investment manager. As part of the firm's pan-European equities team, he managed the $44.1 million ($63.7 million) Aberdeen Smaller Companies High Income investment trust, which generated a total return of 75 per cent over the last five years, according to FE Trustnet.

He joins the team led by the firm's head of European equities, David Moss. Webster's appointment comes a week after that of Gilles Ouellette as interim co-chief executive of the firm, replacing Barry McInerney. Ouellette has served as BMO Financial Group's head of wealth management since 2001.

BMO Global Asset Management had over £160 billion in assets under management as of the end of March 2016.