MSFT 16.96, -0.21, -1.2%) deputy general counsel of intellectual property, Horacio Gutierrez, said in a statement that the software giant filed suit "after attempting for more than a year to engage in licensing discussions with TomTom."

The patents involved relate to "innovations in car-navigation technology and other computing functionality," and have been licensed by other, unnamed companies, according to Gutierrez.

"We remain open to quickly resolving this situation with them through an [intellectual-property] licensing agreement," he said.

Microsoft has made a concerted effort in recent years to sharpen the business focus of its prodigious research, securing legal protections for its steady stream of innovations and then securing licensing revenue through them.