Microsoft Corp. will invest $300 million in Barnes & Noble Inc.’s digital and college businesses, valuing them at $1.7 billion, Reuters reported.

Microsoft will get a 17.6 percent stake in the new unit, and Barnes & Noble will own about 82.4 percent, the companies said in a statement today.

The business, whose name has not yet been decided, will have an ongoing relationship with Barnes & Noble’s retail stores.

Barnes & Noble, the No. 1 U.S. bookstore chain, said in January that it might spin off its digital business, which includes its Nook e-reader.

The companies will introduce an application for the Nook on Windows 8, the upcoming version of Microsoft’s operating system.

Barnes & Noble is investing heavily to develop its popular Nook devices and the e-books sales they generate as readers move away from traditional books, Reuters said.

Barnes & Noble and Microsoft have settled their patent litigation, the companies said.

Shares of Barnes & Noble were up 79 percent at $24.50 in premarket trading today. The company was valued at just above $823 million at close of markets on April 27.