WASHINGTON, March 21 – In a ruling affecting millions of people in thousands of workplaces across the country, the Supreme Court declared March 21, 2001 that employers can compel their workers to take job-related disputes to arbitration.

The 5-to-4 decision means that companies can require employees to give up the opportunity to file lawsuits over disagreements linked to their work and, in fact, can make the surrender of that opportunity a condition of hiring.

The case, Circuit City Stores Inc. v. Adams, No. 99-1379, had been watched by businesses and workers across the nation. The attorneys general of 22 states, fearing that the High Court would undercut state employment laws, had filed friend-of-the-court briefs in an unsuccessful attempt to persuade the justices not to rule as they did today.

Many companies favor arbitration on grounds that it ends disputes relatively quickly and cleanly and without time-consuming and costly litigation. Many workers’ groups contend that arbitration is rigged in favor of the companies, who in effect get to write the rules for the process.