Qlik ,the King of Prussia-based data-analytics company, says it has purchased publicly-traded Attunity Ltd., a Massachusetts-based “provider of data integration and big data management software solutions,” for $560 million.

That works out to $23.50 a share, or an 18 percent premium to Attunity’s recent trading price, and an 18-year high for the stock. Both boards have approved the sale pending Attunity shareholders’ ratification, which the companies expect this spring.

The deal follows last year’s acquisition by Qlik of another Massachusetts business software firm, Podium Data. Since Qlik was purchased for $3 billion and taken private by Chicago-based investment firm Thoma Bravo in 2016, the company has bolted on a series of acquisitions to broaden and update its sales to large companies.

“Attunity has demonstrated strong growth in a large market and together we’re better positioned," said Qlik chief executive Mike Capone in a statement. The company also offers “data lake management and cloud infrastructure partnerships” with Microsoft, Amazon AWS and other remote providers.