The Senate voted 66-31 in favour of the Chile trade bill and 66-32 for Singapore, reflecting strong bipartisan backing for both bills. The House of Representatives passed the agreements last week by wide margins.

A coalition of manufacturers, farm groups, high-tech entertainment and services companies backed the agreements, which add to existing US free trade deals with Canada, Mexico, Jordan and Israel.

Labour groups lobbied against both deals, saying they take away jobs.

"Tonight's strong margins of victory show that when real free trade agreements with tangible benefits for businesses, workers, and consumers are on the table, Congress will have open markets for America," said US Trade Representative Robert Zoellick.

Sen. Charles Grassley, an Iowa Republican, praised the two deals as "state-of-the-art agreements" and Sen. Orrin Hatch, a Utah Republican, said the Chilean pact was a "very important step" in building up support for the United States in Latin America.

President George W Bush has 10 days to sign the bills.

The White House hopes the Chilean pact will set the state for a free trade deal with five Central American countries and a more ambitious 34-nations Fee Trade Area of the Americas.

The Bush administration is also negotiating deals with the Dominican Republic, Australia, Morocco and South Africa.

The trade pacts with Chile and Singapore put the United States "back in the game on international trade," said Bill Morley, vice president of congressional affairs at the US Chamber of Commerce. "We're thrilled to have them pass it."

The Chile agreement is more far-reaching than the Singapore pact and includes provisions to free agricultural trade completely within 12 years.

But senators from both sides of the aisle voiced concerns over provisions that award 6,800 work visas per year to professional workers from both countries under preferential conditions at a time of rising unemployment.