Dido Harding will step down as TalkTalk Telecom Group PLC's CEO in May, after seven years in the role.

Harding will be replaced by Tristia Harrison, managing director for TalkTalk's consumer segment, according to a Feb. 1 news release. From May, Charles Dunstone will assume the role of executive chairman of the British provider of mobile, pay TV and broadband services.

Harding intends to focus on her activities in public service.

Meanwhile, Charles Bligh, managing director for TalkTalk's business segment, will become the company's COO.

A serious cyberattack in October 2015 costed the company around £60 million and led to a loss of more than 100,000 customers.