Clearing more legal challenges, Microsoft Corp. announced important settlements Monday with rival Novell Inc. for $536 million and with a Washington-based trade organization that had aggressively backed landmark antitrust cases against Microsoft by the U.S. government and European Union.

Novell and the trade group, the Computer and Communications Industry Association, agreed to pull out of the legal case against Microsoft in the European Union, which earlier this year declared Microsoft guilty of abusing its dominant position in the technology industry. A key ruling on sanctions against Microsoft is expected as early as this month.