Washington ? Nine states asked a judge Monday to impose tougher penalties against Microsoft, citing internal memos as evidence the software giant had persisted in thwarting competitors even as it was being found guilty of antitrust violations.

The states, including Kansas, asked U.S. District Judge Colleen Kollar-Kotelly to force Microsoft to create a stripped-down version of its flagship Windows software that could incorporate competitors’ features and to divulge the blueprints for its Internet Explorer browser.

The latter software dominates the Web browser market and is a centerpiece of Microsoft’s Internet-based business strategy.

Microsoft lawyers countered that the proposed penalties would force the company to pull Windows off the market. “At the end of the day, the product would have very little value,” lawyer Dan Webb argued.

Both sides made opening statements in a court proceeding to determine whether Microsoft should face additional penalties beyond those in its antitrust settlement with the federal government last fall.

The states opened their case by airing Microsoft executives’ words in e-mails and internal memos detailing how the company responded to threats from competitors.

Dell Computer had plans to put Linux, a free operating system that competes with Windows, on some of its computers in 2000, the states’ lawyers said. But Dell abandoned the plans under pressure from Microsoft, they said.