Conor McGregor has vacated his featherweight title, ending his time as a two-division champion, UFC has confirmed.

The Irishman won the title when he knocked out Jose Aldo at UFC 194 in December 2015 but has never defended the belt. The move means Aldo reclaims the title – he had previously threatened to leave UFC after he failed to land a rematch with McGregor.

McGregor remains the lightweight title holder, after beating Eddie Alvarez in New York earlier this month. McGregor had spoken of his desire to keep hold of both belts. Last week his agent, Audie Attar, was asked if his client would fight any attempt to take one of his titles. “He’s a businessman, so he is going to make business decisions,” Attar said. “No matter what happens, nobody will ever be able to take those belts away from him. Nobody has beat him for those belts. So the way I look at it is, whatever business decision Conor decides to make, it’s a smart one. We have proven that to date. If a belt is taken or what have you, it’s figurative. He still keeps that win. Nobody beat him to dethrone him.

The UFC president, Dana White, says McGregor is unlikely to fight before May 2017, with his partner, Dee Devlin, expected to give birth to their first child early next year. “He’s good. He should take time off,” White said. “He has been fighting nonstop. Nothing wrong with him taking time off. It’s good for him and [Devlin], and it’s good for the baby.”