The definitive agreement signed by the two companies involves an all-cash purchase of Attunity shares at US$23.50 per share.
That is an 18% premium on Attunity's closing price on 20 February (US$19.93 per share) and values the company at approximately US$560 million.
The agreement was unanimously approved by both boards of directors.
"Attunity's strength in real-time data delivery across complex cloud environments will uniquely position Qlik to help customers lead with data and align their enterprise analytics strategy," said Qlik chief executive Mike Capone.
"Attunity has demonstrated strong growth in a large market and together we're better positioned to serve our enterprise customers along with our partner ecosystem to solve the most challenging data problems."
Attunity chairman and chief executive Shimon Alon said "We are excited to be joining Qlik, combining our data integration and big data management capabilities with the analytics leader to accelerate our success.
"We believe the transaction is in the best interest of Attunity's stakeholders and provides Attunity with additional awareness and scale to execute our strategic plans as we continue to provide our customers with the premier products and services they have come to expect."
In addition to being able to take advantage of Attunity's technology, Qlik also expects to benefit from its partner network, which includes Amazon AWS, Cloudera, HPE, IBM, Microsoft, Oracle and Snowflake. The company has an impressive customer list, including Dolby Laboratories, Ford, GDF Suez, Northrop Grumman, Pfizer, Mercedes Benz USA,
The deal, which is subject to customary closing conditions, is expected to close in the second quarter.