"I don't expect our allies will be pleased with this legislation, but we believe it advances an important part of our foreign policy," the official said.

Another provision would allow American citizens whose property was confiscated by the Castro Government to file suit in the United States against any foreign company using that property. But in a concession to win the support of the Administration, it would give the President the right to waive that rule every six months to keep the courts from being choked with lawsuits.

No other nation observes the United States embargo on Cuba. Canadian, Mexican and French companies, among others, have sizable investments there. Canada, for example, imports about $225 million of Cuban goods a year and sends Cuba about $160 million worth of Canadian goods. Canada is expected to challenge the policy under the North American Free Trade Agreement. Only last summer, Secretary of State Warren Christopher recommended that Mr. Clinton veto this bill. But Cuba's downing of the planes, which had taken off from Florida, put enormous political pressure on the President to act decisively. Mr. Clinton only narrowly lost Florida to George Bush in 1992, and the state is considered a key battleground in this election year.

On Monday, President Clinton imposed limited sanctions against the Cuban Government, closing off charter air routes, restricting the movements of Cuban diplomats in the United States and expanding the broadcasting range of Radio Marti, the Government-supported anti-Castro radio station.

But Mr. Clinton's actions were roundly criticized as weak and ineffective by some Cuban-American leaders, by Congressional Republicans and by nearly all of the Republican Presidential contenders. And when Congress reconvened on Tuesday after a nearly monthlong recess, supporters of the stronger bill moved immediately to revive it.