Microsoft broadened its attack on Google's Android software, filing patent infringement lawsuits against Barnes & Noble and two manufacturers over the Android-based Nook e-reader.

In the complaint filed in the US District Court of Seattle on Monday, Microsoft seeks triple damages for wilful and deliberate patent infringement and an injunction against further infringement. Microsoft said it also filed a complaint with the International Trade Commission, which has the power to bar imports of infringing products.

Microsoft's lawsuits don't go after Google directly, but could still hurt if device makers decide they don't want to pay to license Microsoft's technology or risk a legal tussle with the deep-pocketed software maker.

- BLOOMBERG