The private-equity giant headed by billionaire Stephen Schwarzman is acquiring 75 percent of the family history research business for $4.7 billion, Bloomberg reports.

The acquisition would be the first for Blackstone’s massive $25 billion private equity fund.

The deal has been in the works for several months, according to the report, and may be announced as soon as Wednesday.

Ancestry.com’s popular tests generally use saliva to determine the user’s ethnic heritage. It has run ad campaigns showing people who have found family members they didn’t know about through the service.

The Pentagon last winter warned service members to stay away from DNA kits if they got one as a Christmas gift, warning that the genetic tests could put their private data at risk of exploitation by third parties.