McGraw-Hill Companies, a New York-listed data and publishing company, takes a stake in e-book partner.

McGraw-Hill Companies, a New York-listed data and publishing company, has agreed to acquire a 20% stake in Denmark-based adaptive learning company Area9, according to news provider TechCrunch.

Earlier in the month at the Consumer Electronics Show, the McGraw-Hill Education division showed its adaptive electronic SmartBook for students that changes as a reader answers review questions placed throughout the chapter. The SmartBook was developed with Area9.

In late November, McGraw-Hill agreed to sell for $2.5bn the education business to private equity…