Following Microsoft's lawsuit against TomTom for what the software giant said was the infringement of eight Microsoft patents, TomTom has filed a countersuit.

TomTom says that Microsoft infringes on four of its patents in Microsoft Streets and Trips. The GPS company is demanding triple damages for "wilful infringement", as it claims Microsoft had been notified of the issues.

Horacio Gutierrez, corporate vice president and deputy general counsel of Intellectual Property and Licensing, Microsoft said in response to the news:

"We are reviewing TomTom's filing, which we have just received. As has been the case for more than a year, we remain committed to a licensing solution, although we will continue to press ahead with the complaints we initiated in the US District Court for the Western District of Washington and the International Trade Commission".