An abrupt change at the helm of Symantec, the US antivirus maker, sent shares in the company sharply lower yesterday, capping a challenging year for a firm that remains one of the worst-performing members of the S&P 500.

Symantec said it had replaced chief executive Steve Bennett with Michael Brown, a board member, as interim chief executive. Mr Bennett, who had been in post for less than two years, drove the software maker into new markets, including securing companies against data breaches.

A source said the board was concerned about Mr Bennett’s e product strategy, particularly as product development leaders departed to competitors.

Jefferies analysts have downgraded the company to hold from buy, raising the concern of additional exits . – Copyright Financial Times Limited 2014