The Supreme Court will on Wednesday test the global reach of US patent law, in a case that could have big implications for new technology industries such as software and biotechnology.

The case concerns whether Microsoft should be liable for damages overseas for infringing a software patent owned by AT&T for the manufacture of synthetic speech. It will test the extraterritorial application of US patent law in the information age at a time when courts around the world are struggling to apply national laws to increasingly globalised economic activity.