TalkTalk chief executive Dido Harding is to leave the telecoms group in May after seven years in charge.
Baroness Harding will be replaced by current managing director Tristia Harrison, while founder Sir Charles Dunstone will become executive chairman after stepping down as chairman of Dixons Carphone in May.
TalkTalk, whose business arm is based in Warrington, said revenues fell in the final months of 2016. News of the shake-up saw shares rise more than 6% in early trading. The shares had fallen more than 20% in the months following the high profile cyber attack.
Baroness Harding, a Conservative peer, said: “Between now and May, we will work together on a handover that maintains focus on this year’s performance and enables the new team to prepare for the next financial year and beyond.”
Baroness Harding, who was appointed in October 2010, was chief executive when hackers attacked the company’s website in 2015, stealing confidential customer data. TalkTalk estimated the cyber-attack cost it £42m.
The company was fined a record £400,000 in October for poor website security leading to the theft – the largest ever fine imposed by The Information Commissioner’s Office.
Dunstone, who created TalkTalk in 2002, said Baroness Harding had “helped transform TalkTalk into a much stronger business”. Meanwhile, the company announced that revenues had fallen to £435m, from £459m for the same period a year ago.
TalkTalk blamed the fall on a high level of contract renewals and new price deals, but said the impact of this was “short-term”.