Dunbar, who is set to make his Team Sky debut on Saturday at Coppa Agostoni, has agreed a deal to the end of the 2019 season.
The Irishman, 22, was contracted to Aqua Blue Sport for the 2018 season, but – following the closure of the team – Aqua Blue and the UCI have granted Dunbar permission to leave his contract early and sign for Team Sky.
Dunbar has certainly caught the eye in 2018, racing to an impressive eighth at both the Tour de Yorkshire and Tour de l’Avenir, and he will hope to carry that form into the Italian Classics, in the colours of Team Sky.
“I’m really grateful for the opportunity I’m getting after the situation I’ve found myself in,” Dunbar told TeamSky.com.
“Sometimes a team folding is the way the sport goes. I just had to be professional about it and understand the situation. Luckily Sky came along and they offered me a block of Italian races which is good preparation for Innsbruck.