Haig has had a solid year of racing at the top level, playing a major support role for the team at the Giro d'Italia before taking on a leadership position at the Tour de Suisse and placing third overall at the Tour of Utah.
“In some ways, Jack has been performing on a higher level than we had actually planned," Sport Director Matt White said. "So we wanted to reward him for that with a new contract for next year and an additional year on top of that.
"It’s a win-win for all of us. It’s a reward for him, but we also have the knowledge that the relationship works and that we both want to commit to a longer future together.”
Haig, 24, who started as a neo-pro with Mitchelton-Scott, is now locked in until 2020 with a view to further development as a week-long race team leader.
“The goal I’d like to go into the next two seasons with is trying to take more responsibility in the week-long Tours and having a bit more of a leadership role there," Haig said.
"I also love working for the two Yates brothers and Esteban so I hope to continue in that role like I did at this year’s Giro d’Italia, and hopefully help one of them to win a Grand Tour in the next couple of years."