The two ships, which will continue to operate under the Crystal Cruises brand which has also been acquired by the group, will resume service in 2023 after undergoing refurbishment.
Silversea founder and co-chair of A&K Travel Group, Crystal Cruises and Abercrombie & Kent, Manfredi Lefebvre d’Ovidio, said he "did not think twice" when the opportunity arose to acquire the brand.
"I am thrilled to start this new chapter and to be back in an industry that has always had, and always will have a special place in my heart," he added.