The head of sales at Troika Dialog has become the third senior banker at the Russian brokerage to step down in less than three months, after leaving his position to go on "academic leave".

Gerrit Heyns, who has stepped down from his position after joining Troika in 2002, follows the resignation of the firm's UK chief executive Howard Snell and the departure of Giedrius Pukas, the managing director of Troika Capital Partners in late May.