The squad had already announced in December 2020 that it would revert to Independent status next year after seven seasons as Aprilia's factory team.
The deal which has indeed come to pass with MotoGP's other Italian manufacturer is for two years, although the specification/s of its bikes has/have not yet been disclosed.
It marks the latest evolution of Gresini Racing following the death of its founder Fausto in February after battling with COVID-19 from the final days of 2020.
His widow, Nadia Padovani, was named the new team principal in April, with sons Lorenzo and Luca to also work in the running of the team.
“It's a very emotional moment for each of us,” said Padovani.
“In previous months, our efforts merged with a strong emotional push to shape the future of Gresini Racing, and now are immensely proud and happy to make the official announcement.
“It is a project born out of continuity and based on values upon which Fausto built this amazing institution.
“My thank you goes first and foremost to Carmelo Ezpeleta [Dorna Sports CEO] for making sure we never felt alone during these months, to Ducati for trusting our projects, to Flex-Box who joined us in this new challenge as title sponsor and obviously to Fabio and Enea: I'm sure they will give their best to wave the Gresini Racing banner high.”
According to Ducati Corse's general manager, Gigi Dall'Igna, the deal has been in the works since late last year.
“We're incredibly happy to have reached this agreement with Gresini Racing for the next two MotoGP seasons,” said Dall'Igna.
“We had laid down the foundations of a possible agreement with Fausto already at the end of last year and we would like to thank – from the bottom of our hearts – his family for carrying this project forward with us.
“Gresini Racing has been an especially important institution in MotoGP for many years and we are confident this partnership, which can count on two very talented riders such as Enea and Fabio, will be of great satisfaction for all parties involved.”
Ezpeleta commented, “First of all, it is a pleasure to continue working with Gresini Racing as an Independent Team.
“I know how much Fausto cared about this project and I'm sure he would be very proud of it now.
“I had the opportunity to speak with Nadia in recent weeks and I see in her, in her sons and the whole team the determination and the great passion for this sport that characterised him so much.
“We're thrilled that Gresini Racing will continue, at least, five more years in the Premier Class.”
Di Giannantonio is already part of the Gresini family in its Moto2 squad, and currently holds fifth in the championship with one victory thus far in 2021.
Bastianini moved into the premier class this year to ride for Esponsorama Racing (‘Avintia'), which is effectively being replaced on the grid in 2022 by Valentino Rossi's Team VR46.
The switch means he will continue to ride a Ducati in MotoGP, although VR46 also appears likely to link with the Bologna marque when it becomes a premier class outfit in its own right.
Round 8 of the season takes place this weekend at Germany's Sachsenring.