BT’s chief strategy officer, Sean Williams, is leaving the company amid a wider restructuring of the telecoms giant.

Mr Williams, who currently heads up the group’s strategy, regulation and policy unit, is understood to be being replaced in the coming months.

Mr Williams - whose departure was first reported by the Financial Times - joined BT in 2008 from regulator Ofcom, where he was a board director.

BT has seen a number of senior departures over the past 18 months, including its chairman, finance director, head of corporate affairs and head of investor relations.

The group is also in the process of a legal separation from its network unit Openreach, signing a deal in March with Ofcom following two years of fraught negotiations.

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Investors have been spooked by other problems including a black hole in the accounts of the company's Italian business and a record £42m fine for delays in installing fibre-optic cables for rivals.

Jan du Plessis, a former chairman of mining group Rio Tinto, will take over as chairman of BT in November.

BT’s share price has plummeted by almost a quarter (24pc) over the past 12 months, closing today at 304.25p.

Clive Selley, chief executive of Openreach, told The Sunday Telegraph at the weekend that Openreach is close to a deal with the Government to deliver broadband upgrades to more than a million rural homes.

BT declined to comment.