Microsoft added this week to the billions it has paid to settle antitrust lawsuits brought by competitors, agreeing to pay $536 million to rival Novell Inc. The world's largest software company also settled with a trade organization that it has done legal battle with for years, the Wall Street Journal reported.

Microsoft also settled with Computer and Communications Industry of America (CCIA), a Washington-based trade organization that had fought for tougher sanctions against Microsoft in the U.S. and had backed an antitrust suit brought against Microsoft by the European Union. CCIA members include Microsoft rivals Oracle Corp., Sun Microsystems Inc. and Red Hat Inc., the Journal reported.

Microsoft has paid out billions in recent years to settle antitrust lawsuits and faces up to $950 million in further liability in ongoing cases, the company disclosed.

The dispute with Novell revolved around Novell's NetWare operating system, which competes with Microsoft Windows, the Journal reported. As part of the settlement, Novell agreed to withdraw from the European Union's antitrust lawsuit against Microsoft, the Journal reported.

A dispute between the two companies over WordPerfect was not resolved by the settlement. Novell, which owned WordPerfect from 1994 to 1996, plans to file suit this week in Utah against Microsoft, claiming Microsoft acted illegally in the 1990s when Microsoft's Word surged ahead of WordPerfect in the market. Microsoft has indicated it plans to let the courts decided that matter, the Journal reported.

As part of its settlement, CCIA agreed to its plans to seek a Supreme Court review of the Microsoft's settlement with the Justice Department and will no longer participate in the European case against Microsoft, the Journal reported, with Microsoft agreeing to join the group and pay an undisclosed amount of "legal-related" expenses.

Brad Smith, Microsoft's general counsel, said company has now resolved disputes with four of the five major participants in the European case.

"Clearly, there is less need for the EU to persist" with its lawsuit against Microsoft when "virtually all of the competitors say their issues have been resolved to their satisfaction," Smith told reporters Monday. "We are prepared to sit down with anyone to find common ground."