MPE started in 1985 as a division of Mercury Asset Management (MAM) that was already running two business expansion funds, which it had raised. In that year, the firm gained its first institutional client. A new management team was put in place and MPE started participating in more conventional private equity activity such as buyouts.
In 1994, MAM acquired Grosvenor Venture Managers, a venture firm that had five funds including an investment trust. The firm was doing deals, but was having problems raising another fund and so MAM took on the task of running the Grosvenor portfolios. Through the acquisition, MAM acquired the management contract for Mercury Grosvenor Trust (MGT) which had shareholder funds of GBP12 million. MPE still manages this investment trust today, allowing private investors to get exposure to its investments. MGT now boasts shareholder funds of some GBP120 million.