Drug giant GlaxoSmithKline (NYSE: GSK) made news official Thursday what had been rumored for months: CEO Andrew Witty is going to retire. Witty plans to step down a year from now.

Witty has been CEO for a decade.

The search for a successor comes amid months of pressure from some investors, who had wanted the diverse company to be broken up.

The company said in a statement that Witty believes “this will be the right time for a new leader to take over.” The move is effective in March 2017.

Citing media reports in the U.K., WRAL TechWire reported last month that GSK had launched a search for a successor.

“GSK is a very special company with an inspiring mission and many dedicated people,” Witty said in a statement.

“By next year, I will have been CEO for nearly ten years and I believe this will be the right time for a new leader to take over. In making this decision it has been important to me that the Board have the time to conduct a full and proper process and that we sustain the momentum of our current business performance, capitalising on the very significant progress we made last year to strengthen the Group. By doing so we will strongly position GSK to achieve the medium-term outlook set out to investors last year and deliver a return to core earnings growth in 2016.”

Like many big pharmaceutical companies, GSK has struggled to see off the challenge of generic drugmakers and come up with new blockbuster drugs to replace medicines with expiring patents.

It has also faced other challenges. Britain’s competition authority has fined GSK 37.6 million pounds ($54.5 million) for stalling the potential entry of generic competitors of anti-depressant drug Seroxat into the marketplace.

GSK employs several thousand people in the Triangle area, including at a production plant in Zebulon and a research campus in RTP.

GSK’s formal announcement

Sir Andrew Witty to retire from GSK in March 2017

In the publication of its 2015 Annual Report to shareholders, GSK plc today announced that Sir Andrew Witty, CEO, has indicated to the Board his intention to retire from the company in early 2017. The Board has agreed that he will retire on 31st March 2017. The Board will now conduct a formal search for a successor and will consider internal and external candidates for the role.

Sir Philip Hampton, Chairman, said: “Andrew’s retirement next year will represent the culmination of 32 years of service and leadership to GSK and the industry. We will thank Andrew more formally for his tremendous dedication and contribution next year. In the meantime, we will now start a formal process to appoint his successor, whilst also ensuring the Group remains focussed on execution of its strategy to drive growth and performance.”

Sir Andrew Witty, CEO said: “GSK is a very special company with an inspiring mission and many dedicated people. By next year, I will have been CEO for nearly ten years and I believe this will be the right time for a new leader to take over. In making this decision it has been important to me that the Board have the time to conduct a full and proper process and that we sustain the momentum of our current business performance, capitalising on the very significant progress we made last year to strengthen the Group. By doing so we will strongly position GSK to achieve the medium-term outlook set out to investors last year and deliver a return to core earnings growth in 2016.”