WASHINGTON (Reuters) - The U.S. government on Monday opposed Microsoft Corp.'s effort to throw out claims against it by nine states on grounds that a proposed antitrust settlement has already been reached with the federal government.

While questioning the wisdom of the states' proposals, the Justice Department (news - web sites) said states refusing to back its settlement with Microsoft have the authority to pursue more severe antitrust sanctions, despite company claims to the contrary.

Microsoft statement:

This afternoon, the Department of Justice filed an amicus brief, in response to a request by the Court, on our Motion to Dismiss.

The following is a statement you can use on behalf of the company on today's filing by the DoJ.

We are gratified that the Department of Justice has weighed in to support major elements of our motion to dismiss as well as the key points we made in our motions for judgment as a matter of law filed in court today. In their brief, the DOJ acknowledges that our Motion to Dismiss raises important issues of federal antitrust enforcement policy that are significant in the Court's ultimate decision on this case.

The brief also confirms that the non-settling States are required to prove that they have sustained an antitrust injury as aresult of Microsoft's actions, which the States did not do in their case-in-chief.

In addition to all of Section III of the DoJ brief (p. 21-26), the following excerpts underscore these points.

p. 15-16

The United States, of course, strongly believes that entry of the proposed final judgment in No. 98-1232 is very much in the public interest. Further, the United States recognizes the danger that the relief being sought by the non-settling States - much of which diverges from the SRPFJ, but from any theory advanced or relief sought by the United States and the States earlier in this litigation - may harm consumers, retard competition, chill innovation, or confound compliance with the SRPFJ. The United States is hardly indifferent as to the wisdom or propriety of granting such relief in this case.

p.26

The non-settling States' remedial proposals are vast in their scope and potential impact upon the information technology sector of the U.S. economy and beyond. They diverge from the proposed settlement not so much in their approach to prohibiting the specific conduct found by the Court of Appeals to be acts of monopoly maintenance, but rather in their effort to extend the relief to new products, new services, new markets, and even new theories of liability in the name of deterring future violations as a prophylactic matter. Given the nature of state standing under Section 16, the Court may properly inquire in the exercise of its equitable discretion whether a small group of States are the parties best situated to obtain relief of such broad reach and implication.

Proposed remedies without a clear basis in the decision of the Court of Appeals risk straying from appropriate antitrust enforcement grounded in law. Proposed remedies that chill legitimate innovation and product improvement - even by a monopolist - can deprive the public of significant competitive benefits. Perhaps most importantly, remedies that conflict with or undermine the enforcement judgments reached in the SRPFJ endanger our practical system of coordinated national antitrust enforcement. These considerations become magnified in significance when, as here, the competitive issues are national in scope, the plaintiffs seeking relief have neither the authority nor the responsibility to act in the broader national interest, and the plaintiff with that authority and responsibility has taken a different course. The emphasis upon the equitable powers of the Court in Clayton Act Section 16 is the means provided by federal antitrust law to avoid enforcement authority in this extraordinary case.