Westfield-based MaxIT Healthcare Holdings Inc. has agreed to sell itself for $473 million to Virginia-based Science Applications International Corp., the companies announced Tuesday night.

MaxIT’s 1,300 employees provide information technology services to hospitals and physician practices throughout the United States and Canada. Those workers will be combined with Vitalize Consulting Services, which SAIC acquired last year to focus on implementing electronic medical record systems.

Only about 75 of MaxIT’s employees are in Westfield. The company is riding a wave of hospitals’ and medical offices’ switching or adding computer systems to better track patient records, CEO Mike Sweeney told IBJ earlier this year.

MaxIT saw revenue shoot up 63 percent in 2011, to $179.4 million.

"The combined strengths of MaxIT, SAIC and VCS will be a significant differentiator in the health care IT market,” said Sweeney in a prepared statement. “We look forward to continued growth as part of the SAIC team, while maintaining flexibility to meet the ever-changing needs of the health care market.”

The acquisition is expected to close in August 2012. SAIC will pay cash for MaxIT. After closing, it expects to earn tax refunds related to the deal that will put another $20 million into the pockets of MaxIT shareholders.

MaxIT was founded in 2001 by Parker Hinshaw. Healthcare Informatics, a trade journal, ranked MaxIT the 41st largest health IT firm in the nation in 2011, based on revenue.

SAIC ranked No. 18 in the nation with revenue from health IT businesses topping $554 million. SAIC also performs a variety of secret work for the U.S. departments of defense, homeland security and the U.S. intelligence community.