Current Ancestry investor GIC will retain a minority stake in the company.
David Kestnbaum, a senior managing director at Blackstone, said: “We believe Ancestry has significant runway for further growth as people of all ages and backgrounds become increasingly interested in learning more about their family histories and themselves.”
He added that Blackstone would invest in “further data, functionality and product development” at Ancestry.
On its blog, Ancestry said: “Blackstone’s acquisition will further accelerate Ancestry’s global leadership in Family History and consumer genomics.”
It added: “Our robust consumer privacy and data protections remain unchanged under our new ownership.”