Apple’s chief operating officer plans to hand the role off this month and retire later this year after roughly a decade as the tech giant’s No. 2 under Chief Executive Tim Cook.

A once leading candidate to replace Tim Cook as Apple’s CEO announced his retirement Tuesday. Chief Operating Officer Jeff Williams, who has worked at Apple for 27 years, will be replaced in a “long-planned succession” by Sabih Khan,

Apple has announced that Sabih Khan, the company’s vice president of operations, will take over for Jeff Williams as chief operating officer later this month. In an announcement on Tuesday, Apple said the move is part of a “long-planned succession” that has Williams retiring at the end of this year.