One of the five executive directors at Numis has cashed in her entire stake in the UK stockbroker for nearly £17m, as she prepares to step down from its board this month and leave the firm at the end of the year.

Lorna Tilbian, who has worked at Numis for more than 16 years, runs the firm's media banking team and was the top-ranked analyst in the sector by Institutional Investor and Thomson Reuters Extel between 1987 and 2012, according to Numis' website.