His responsibilities as head of third-party distribution, working closely with platforms and life companies, will now be taken on by Mark Allpress, head of UK sales, who Morrissey reported to.
A spokesman for Liontrust confirmed that no decision has yet been taken on whether or not to recruit a replacement. It is not known what role, if any, Morrissey will be taking on next.
Morrissey joined the firm a decade ago from a similar position with Merrill Lynch Investment Managers, reporting as head of distribution to the then chief executive Nigel Legge.
His departure follows Ian Furtado leaving his position as head of sales at Occam in March following its acquisition by Liontrust. Since May he has been a business development manager at Royal London Asset Management.