Sir Mike Rake to retire from BT in November after serving 10 years as chairman.

BT on Thursday announced that chairman Sir Mike Rake will retire later this year, and will be succeeded by Rio Tinto chairman Jan du Plessis.

South African-born du Plessis will join the U.K. incumbent as a non-executive director on 1 June, and will step up as chairman on 1 November, when Rake departs.

"I am honoured to have been asked to become BT’s chairman. BT is a great British company with excellent people and Mike has done an outstanding job as chairman over the last 10 years," du Plessis said.

Du Plessis has been chairman of mining giant Rio Tinto since 2009. He has also served as chairman of multinational brewer SABMiller, and as senior independent director of retailer Marks & Spencer.

"Jan is the unanimous choice of the board," said Nick Rose, BT’s senior independent director, who led the process to appoint a new chairman.

"Our desire was to find someone with deep experience of leading high profile organisations and who would also have credibility with our key stakeholders. We ran a thorough process to ensure we identified the very best candidate to lead BT," he said.

Rake was named BT chairman in February 2007. He joined the telco from accountancy firm KPMG, succeeding Sir Christopher Bland, who stepped down in September of that year.

Rake leaves a company that is succeeding in some areas, but facing challenges in others.

BT’s consumer business continues to attract new customers with its aggressive push into TV, and it is now the country’s largest mobile operator by subscribers thanks to the EE acquisition.

However, BT’s share price plunged in January when it emerged that accounting errors at BT Italy were more severe than first thought, leading it to record a £530 million (€613.8 million) writedown, and cut its earnings forecast for the current fiscal year and next year too.

In addition, regulator Ofcom is determined to strengthen the independence of BT’s infrastructure arm Openreach by forcing a legal split of the two companies, all the while rivals like TalkTalk are lobbying hard for a complete separation.

Ofcom is also being pressured by the likes of 3UK and O2 to cap the amount of currently usable spectrum that any single mobile operator can hold at 30%. BT and EE together currently hold 45%.

"Whilst clearly there are continuing challenges, the performance of the company remains on track," Rake insisted. "This gives me great confidence in its future and I wish Jan every success as he leads BT at this important time."