Arbuthnot Securities, the investment banking subsidiary of Secure Trust, has hired Mark Brown as its chief executive, three months after he was ousted from his position as head of equity research at ABN Amro.

In March this year, Brown made a sudden exit from ABN Amro after the bank decided to overhaul its research policy and merge its analyst and sales departments. He had rejoined the Dutch bank in 2002 after a two-year stint as head of equity research at HSBC.