Shares of Manchester-based TalkTalk Telecom Group rose about 9% after it said Dido Harding would step down as CEO in May 2017 after seven years and TalkTalk founder Charles Dunstone would become executive chairman. 

TalkTalk said that from May, non-executive chairman Dunstone — who owns roughly 31% of the firm — would assume the role of executive chairman after stepping down as chairman of Dixons Carphone on May 1. 

Tristia Harrison, currently managing director of TalkTalk Consumer, will succeed Harding as CEO.

Charles Bligh, currently MD of TalkTalk Business, will become chief operating officer.

TalkTalk shares rose to about 169p to give it a current stock market value of roughly £1.5 billion.

TalkTalk has spent more than a year trying recover from a cyber attack in October 2015 that affected 156,000 customers.

Harding commented: “After seven extraordinary and fulfilling years, during which we have transformed TalkTalk’s customer experience and laid the foundations for long term growth, I’ve decided it’s time for me to start handing over the reins at TalkTalk  and focus more on my activities in public service.  

“I am very proud to be handing over to the next generation of TalkTalk leadership who, together with Charles, have played such an integral part in the success of the business to date. 

“Between now and May, we will work together on a handover that maintains focus on this years’ performance and enables the new team to prepare for the next financial year and beyond.”

Dunstone said: “Dido has been a tireless, energetic and effective force for good from the day she joined TalkTalk.

“As a result of her leadership and total commitment to all of us who work here and our customers, she has helped transform TalkTalk into a much stronger business …

“I’m excited at the prospect of spending more time on TalkTalk, beginning with delivering another successful performance this year; and I am delighted to announce the promotion of Tristia and Charles to help me lead the business so that we continue to deliver successfully for our customers and our shareholders.”