The sources added that the Justice Department is looking at other issues as well, including the marketing of the Windows NT corporate operating system, Microsoft's actions in the Java market, and its partnerships with Internet content providers.
The PC companies that recently received subpoenas, known formally as civil investigative demands, included Compaq Computer and Hewlett-Packard, sources familiar with the matter said. A Compaq spokesman confirmed that the company has received a subpoena.
A spokeswoman for Hewlett-Packard said she was not aware of such a request for information. Besides selling personal computers, HP recently announced that it would create and market its own version of Java, the programming language developed by Sun Microsystems.
Regulators' renewed interest in the computer makers comes just weeks after members of the Senate Judiciary Committee offered evidence that seemed to contradict testimony from Dell's chief executive. Testifying at a special hearing last month on competition in the software industry, Michael Dell said that Microsoft in no way bars his company from preinstalling competing Web browsers on the computers it sells.
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Microsoft spokesman Jim Cullinan played down the significance of the civil subpoenas.
"I don't think it's surprising that the Justice Department is talking with some of our largest partners, and we're confident that once they take a look at what Microsoft is doing, in terms of our business practices, they will see we are complying with the law and are focused on building great software products," he said.
The Justice Department has confirmed that it is engaged in a broader investigation but has declined to give more details. Evidence sought in the new round of subpoenas most likely would help regulators in bringing any new case based on the Sherman Antitrust Act.
Compaq declined to say what information the Justice Department is seeking in its latest requests for information. Sources familiar with the case say it may want information that will help regulators decide what types of remedies to seek should a new, broader lawsuit be filed.
While outside observers generally agree that the immanent release of Windows 98 is putting pressure on the government to file a suit aimed at the new OS sooner rather than later, there is less agreement about what effect a scheduled April 21 hearing before a federal appeals court might have on timing. The Justice Department has good reason to wait until after the hearing to file any new suit, so that attorneys have the benefit of any comments made by the three-judge panel.
At the same time, however, the issues on appeal before the U.S. Court of Appeals for the District of Columbia are becoming increasingly moot each day, since they are focused narrowly on the packaging of the Internet Explorer browser with Windows 95. What's more, the decidedly conservative makeup of the panel has led some legal experts to predict that the DOJ is likely side with Microsoft Both factors could steer government attorneys in favor of filing a new case before suffering an embarrassing appearance before the appeals court.
Separately, attorneys for Microsoft will meet in the next week with Justice Department officials to discuss their investigation, said two sources familiar with the matter. According to one, Microsoft requested the meeting more than two weeks ago in hopes of improving communication.