Google must hand over its search results and some of its data to rival companies, a federal judge ruled on Tuesday, a decision that falls short of the sweeping changes proposed by the government to rein in the power of Silicon Valley.

Judge Amit P. Mehta of the U.S. District Court for the District of Columbia said in a ruling that to resolve Google’s monopoly in search, the company must share some of its search data with companies that are “qualified competitors.” The Justice Department had asked the judge to force the company to share even more of its data, arguing it was key to Google’s dominance.

Judge Mehta also put restrictions on payments that Google uses to ensure its search engine gets prime placement on smartphones in web browsers. But he stopped short of banning those payments entirely and did not grant the government’s request that Google be forced to sell its popular Chrome web browser.

The decision on how to remedy a monopoly — the first of its kind in the modern internet era — is the most significant attempt to level the tech playing field since an antitrust ruling against Microsoft more than 20 years ago. Google plans to appeal, and the case is likely to be mired in the courts for years.

This is a developing story. Check back for updates.