U.K. telco names consumer boss Tristia Harrison as new chief executive; Charles Dunstone to become non-exec chairman.

TalkTalk announced on Wednesday that CEO Dido Harding will leave the company in May, after seven years in the role.

She will be replaced by Tristia Harrison, who joined the company seven years ago and currently serves as managing director of the consumer business. Charles Bligh, managing director of TalkTalk Business, will become chief operating officer.

"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," Harding said, in a statement.

Harding will be remembered for her efforts to transform TalkTalk from a no-frills telco provider – one that had a reputation for cold-calling consumers and signing them up without gaining their consent, and had been fined by regulator Ofcom for billing ex-customers – into a respectable quad-play provider pitched as a value-for-money alternative to BT, Sky and Virgin Media.

Harding was making headway, but suffered a setback in October 2015 when TalkTalk fell victim to a significant cyberattack that compromised the personal information of more than 156,000 customers, more than 15,000 of whom had their bank account numbers and sort codes stolen.

Harding has spent the time since then steering the company back on course, while also lobbying for Ofcom to force a full split of BT and its infrastructure arm Openreach.

Meanwhile, TalkTalk also announced that Dixons Carphone chairman Charles Dunstone, founder of Carphone Warehouse – from which TalkTalk was spun off in 2009 – will step down in May and become TalkTalk’s new executive chairman.

"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," Dunstone said.

"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," Harding added. "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."

The announcement was made the same day TalkTalk published its fiscal third quarter financial results.

The company’s revenue fell to £435 million from £459 million a year ago, as price increases led to an uptick in churn. On-net customer additions fell by 42,000.