A group of Microsoft Corp.’s rivals filed a complaint with the European Commission on Wednesday, alleging its business practices threatened to deny real choice among competing software products.

The European Committee for Interoperable Systems — which includes International Business Machines Corp., Oracle Corp., RealNetworks Inc., Nokia Corp. and Sun Microsystems Inc. — said it was asking EU regulators to end practices that reinforced Microsoft’s monopolies and extended its market dominance into current and future products.