In an unprecedented pact, the federal government agreed Wednesday to reconsider tens of thousands of cases involving Salvadoran and Guatemalan nationals whose requests for political asylum in the United States have been denied.

Ending a five-year legal battle, the government also promised to stay many deportations and agreed that "discrimination . . . based on nationality is improper" in asylum judgments.

Critics have long charged that immigration authorities routinely denied asylum sought by applicants from countries with pro-U.S. governments, such as El Salvador, despite widespread civil strife and political killings that might make those countries unsafe.

The agreement, approved Wednesday in a federal court in San Francisco, settles a class-action lawsuit brought in 1985 by 80 religious and refugee-assistance organizations across the nation, some of whom formed part of the so-called "sanctuary movement," which offered a haven to Central Americans fleeing their homelands.

It marks the third time in recent months that the Bush Administration has made a major concession on refugee policy. Only last month, the President signed a landmark immigration reform bill that will grant refugee status for 18 months to thousands of Salvadorans, and the government previously revised the rules for obtaining political asylum.

While the government does not acknowledge past bias or other wrongdoing in its handling of asylum cases, it agrees to rehear an estimated 150,000 asylum cases, according to Marc Van Der Hout, lead attorney for the plaintiffs and a representative of the National Lawyers Guild. The number includes cases that have been denied or are pending.

In addition, 350,000 or more Salvadorans and Guatemalans in the country illegally and who never applied for asylum will also be allowed to seek the protected status, Van Der Hout said.

"This settlement is a major victory for all Salvadorans and Guatemalans in this country whose claims for political asylum were being summarily denied for purely foreign policy reasons," Van Der Hout said as the agreement was announced at a San Francisco news conference.

U.S. District Court Judge Robert F. Peckham issued a preliminary approval of the settlement Wednesday and scheduled a final hearing for Jan. 31.

"We think it is a fair agreement," U.S. Justice Department spokesman Joe Krovisky said in Washington. He declined to discuss the case further.