It didn’t take long for shareholders of Nashville-based Emdeon to threaten a lawsuit over a private equity buyout announced this week.

Blackstone Capital is paying a 17 percent premium to buyout shareholders and take the healthcare IT company private. But attorneys from the Washington law firm Finkelstein Thompson say they’re investigating claims that shares may be worth as much as $21 instead of the $19 agreed to by Blackstone.

A news release says lawyers are looking at the process by which Emdeon’s board considered the deal and potential conflicts of interest.

A lawsuit has not been filed.