Italian newspaper Gazzetta dello Sport reports that although the deal has been made between the 26-year-old Slovak and Astana for the 2017 season, it cannot be confirmed until the official rider transfer date of August 1.
It is likely that Sagan will take with him several key members from Russian team Tinkoff, including his brother Juraj, Oscar Gatto, Michael Kolar and key support staff.
It is thought that American company Specialized Bicycles has been involved with the deal as it is keen for the current world champion to continue riding on one of its bikes. Specialized currently provides bikes for WorldTour teams Tinkoff, Astana and Etixx-QuickStep.
A contract between Sagan and Astana could be worth around €4million per year to the rider.
Sagan would effectively replace Vincenzo Nibali, who is set to leave the Kazakh WorldTour team at the end of 2016 and is linked with a new team from Bahrain. Fabio Aru would be Astana’s main Grand Tour contender.
Tinkoff team owner Oleg Tinkov has decided to end the team and pull out of cycling sponsorship, having said that he is frustrated with the lack of progress in changing the business model of the sport.
Sagan is currently leading the UCI WorldTour ranking, and claimed two stage victories in the Tour of California last week. He enjoyed a successful spring campaign, where he won the Tour of Flanders and Ghent-Wevelgem.
On Monday, Swiss WorldTour team IAM Cycling announced that they would not continue beyond the 2016 season after failing to find a co-sponsor.