Microsoft's LinkedIn on Monday announced the acquisition of Glint, snapping up a start-up whose software helps human resources managers understand how workers feel about their employers.

While terms weren't disclosed, people familiar with the deal told CNBC that LinkedIn paid more than $400 million for Glint, with one source saying that the deal topped $500 million. They all asked to remain unnamed because the price was confidential. A LinkedIn spokesperson declined to comment on the price.

It's LinkedIn's biggest purchase as part of Microsoft, which acquired the professional networking company in 2016, and provides further evidence that Microsoft wants the site to operate independently. Through its subscription businesses, LinkedIn provides a growth market for Microsoft outside its core products like Windows and Office.

With Glint, human resources staffers can survey employees and see how different groups of employees stack up. Glint users can receive alerts when certain teams aren't feeling so good about their work based on results, and managers can receive information in the tool that can help improve their organizations' future survey results.

Microsoft announced its $26.2 billion LinkedIn acquisition in June 2016, the software company's largest deal ever. Microsoft is still willing to write big checks, having recently purchased GitHub for $7.5 billion. Like with LinkedIn, the plan is to keep GitHub operating independently, Microsoft CEO Satya Nadella said earlier this year.

In Microsoft's most recent fiscal year, which ended on June 30, LinkedIn's revenue surged 130 percent to $5.3 billion. Last month Microsoft said that it will start including commercial revenue from LinkedIn — through premium subscriptions, LinkedIn Recruiter, Sales Navigator and other services for organizations — in a key metric for investors called Commercial Cloud.

Founded in 2013, Glint is based in Redwood City, California, and has more than 200 employees, according to data on LinkedIn's website. Customers include Alphabet's Waymo, Dish Network and United Airlines.

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