Microsoft Corp., still the subject U.S. Justice Department scrutiny for allegedly unfair trade practices, Friday was accused by a competitor of making false claims to promote its word-processing program, Microsoft Word.

In a lawsuit filed in federal court in Manhattan, WordPerfect Corp. disputed recent advertising, sales and promotion campaigns that herald Word as the world's most popular word processor. WordPerfect, based in Orem, has long laid claim to being the leader in word-processing software for desktop computers."All the data of which we are aware indicates that WordPerfect is the most popular word processor in the world. We intend to establish that fact in this case," said R. Duff Thompson, general counsel for WordPerfect.

Ken Merritt, spokesman for WordPerfect, said Microsoft ads containing the disputed claim appeared in USA Today and computer magazines. But Word-Perfect was also concerned that Microsoft was "making some very broad-reaching generalities" in its direct sales efforts to business clients.

A spokeswoman for Microsoft, based in Redmond, Wash., maintained that Word is currently outselling WordPerfect worldwide and the company would fight the charges in court.

"What is the definition of most popular, the one who's selling the most right now or the one who historically sold the most?" said Pam Edstrom.

Chris Peters, general manager of Microsoft's Word unit, conceded WordPerfect does have more units installed worldwide and has been outselling Word this year within the United States.

But Peters told the Associated Press the "most popular" claim was based on sales over the past year.

Microsoft cited reports from Dataquest, a market research firm, and the Software Publishers Association, that Word sold more than 3.5 million units worldwide last year, while WordPerfect sold more than 3 million.

Microsoft, the largest computer software company in the world with annual revenues more than six times that of WordPerfect, has been criticized for its business tactics by competitors for several years. The jabs have frequently come from competitors that are losing market share to Microsoft in software applications. Microsoft's own applications programs, such as spreadsheets and word processors, have gotten big boosts from the rapid growth in Microsoft's Windows operating system.

Novell Inc. recently filed an unfair competition complaint with the European Community against Microsoft Corp. Similar complaints resulted in a three-year investigation by the U.S. Federal Trade Commission.

The FTC deadlocked twice on whether to file a formal complaint and turned the case over to the Justice Department in August. The department is conducting its own probe.