SEATTLE — The Internal Revenue Service has sued former Microsoft Chief Executive Steve Ballmer and a slate of other former and current executives, seeking to compel them to testify in an investigation into the company’s tax practices.

The lawsuits, filed in federal court in Seattle, are the latest salvo in a long-running investigation of Microsoft’s tax practices. At issue is whether the company’s various subsidiaries properly followed tax law in transferring software-selling rights to countries and U.S. territories with lower taxes.

The IRS earlier this month sued Microsoft itself to compel the company to turn over a trove of documents as part of its inquiry into how Microsoft valued agreements with subsidiaries in Puerto Rico and Bermuda. The value Microsoft placed on such transfers has “billions of dollars of impact” on the company’s taxable income between 2004 to 2006, the IRS said in that suit.

Microsoft’s lawyers said the company was cooperating with the requests.

According to the latest court filings, IRS agents last month sent summonses to Ballmer and nine other current and former Microsoft executives, including former chief strategy officer Craig Mundie, longtime Microsoft executive and retired Bill & Melinda Gates Foundation head Jeff Raikes and former Windows and server development chief Jim Allchin.

The tax agency wants the executives to be quizzed by IRS agent Walter Choi at its downtown Seattle office.