Tiltman left the firm in August 2014 when the fund was £132 million in size and was replaced by Richard O'Connor who will continue to manage the fund until its closure on 22 May.
A review of the fund was initiated after Tiltman's departure and it has concluded that the fund is unlikely to be commercially viable in the long term.
The fund closure - which has already been approved by the Financial Conduct Authority - is being made to protect the interests of existing shareholders.
Gary Cotton, M&G chief executive of equities said: 'The M&G Global Real Estate Securities fund has failed to attract the level of interest we expected from external investors. Gillian’s departure triggered outflows so it has become increasingly difficult to manage the fund in a cost-effective way.'
Within global property equities over the year to 1 January 2015, O'Connor has produced a return of 35.59% while the average manager has produced a return of 28.28% over the same period.