Former shareholders of Tyco International Ltd., whose former chief executive and chief financial officer were convicted of fraud, have been certified as a class to sue the company and its accounting firm, PricewaterhouseCoopers.

Judge Paul Barbadoro made the ruling Monday in securities fraud cases consolidated in U.S. District Court in New Hampshire. However, he removed one lead plaintiff, Voyageur Asset Management, saying it could not prove it was harmed.