As for now, Microsoft said it has no plans and "sees no value" in sending executives to testify, a spokesman said.
For six months, the company has planned a financial analysts' meeting in the Seattle area on the same day as the hearing, headed by company critic Sen. Orrin Hatch. The annual analysts' meeting will be attended by "virtually the entire executive committee," including CEO Bill Gates.
Senate Judiciary Committee staffers said the complete roster of witnesses still is being drafted. About five witnesses are expected, including the head of a small technology company that is competing against Microsoft. Another witness is expected to reflect Microsoft's perspective.
The hearing marks the third in Congress since November to focus on Microsoft's business practices. Sun Microsystems CEO Scott McNealy and Netscape CEO Jim Barksdale, as well as Gates, have been among those that have testified in the past.
The hearing, dubbed "Competition in the Digital Age: Beyond the Browser Wars," is expected to focus on so-called enterprise computing, including Microsoft's Windows NT, Back Office, and Windows CE. It also is expected to address Microsoft's foray into online content, as well as its Java-related activities.
Microsoft has been sued by both the Justice Department and 20 state attorneys general for allegedly anticompetitive practices. Regulators also are continuing to investigate the software giant. In addition, Microsoft is engaged in a separate legal scrape with Sun concerning its Java programming language.
Last week, the states dropped claims that the marketing of Microsoft Office violated antitrust laws.