Amicas Inc , a provider of healthcare IT services, said it agreed to be bought by an affiliate of private firm Thoma Bravo LLC for $217 million in an all-cash deal.

The deal offers Amicas shareholders $5.35 for each share, a premium of 21 percent over the stock's close on December 24 on Nasdaq.

Amicas expects to close the transaction in the first quarter of 2010, it said in a statement.

Shares of the Boston, Massachusetts-based company closed at $4.42 Thursday.

(Reporting by Vidya L Nathan in Bangalore; Editing by Unnikrishnan Nair)