TalkTalk chief executive Dido Harding is to leave the telecoms group in May after seven years.

Baroness Harding will be replaced by current managing director Tristia Harrison, the broadband provider said.

But TalkTalk also said that founder Sir Charles Dunstone will become executive chairman after he steps down as chairman of Dixons Carphone in May.

TalkTalk, recently fined over a major hacking breach, also said that revenues fell in the final months of 2016.

News of the shake-up sent TalkTalk shares rising 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 and a trustee of digital inclusion charity Doteveryone, said she wanted to focus more on her public service activities.

"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," she added.

Baroness Harding, appointed in October 2010, was chief executive in 2015 when hackers attacked the company's website, stealing confidential customer data.

TalkTalk, for years dogged by a reputation for poor customer service, estimated the cyber-attack, which divulged nearly 157,000 users' financial details, cost it £42m.

The company was fined a record £400,000 in October for poor website security which led to the theft, making it the largest ever fine imposed by The Information Commissioner's Office.

Sir Charles, who created TalkTalk in 2002, said Baroness Harding had "helped transform TalkTalk into a much stronger business".

"I'm excited at the prospect of spending more time on TalkTalk," he added.

Image copyright Getty Images Image caption Sir Charles, the founder of Carphone Warehouse, will remain as a senior adviser to Dixons Carphone

Sir Charles, the founder of Carphone Warehouse, will remain as a senior adviser to Dixons Carphone.

He said the firm, which was created via a merger between Dixons and Carphone Warehouse three years ago, remained "a very important part of my life".

"I remain a committed shareholder and, in my new role as a senior advisor, I will continue to take an active interest in the business," he added.

'Rebuilding trust'

Sir Charles will be replaced as chairman of Dixons Carphone by Lord Ian Livingston, a former chief executive of BT.

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".

George Salmon, an equity analyst at Hargreaves Lansdown, said Sir Charles had to restore the company's reputation.

"His main challenges will be rebuilding trust in the brand and improving relationships with customers," said Mr Salmon.

He added: "For now, though, investors will be relieved that the group says it's on track to meet profit guidance, especially after November's half-year results were less than glowing.

"More customers are now on low-price plans, which isn't exactly what one would want, but the group's hand has been forced by the cyber-attack and defending market share at all costs has had to take priority."