HAVANA -- Cuba put on a lavish welcome for more than 50 U.S. business executives on Friday, urging them to work against an American trade embargo and trying to interest them in now-prohibited business opportunities.

''The main argument against the U.S. policy is that it is not working . . . except in damaging U.S. interests,'' Cuban parliament President Ricardo Alarcon told the group gathered at Cuba's Convention Palace.

Some 37 years after the United States first imposed the embargo against Cuba's socialist government, ''Cuba is still here and the system we chose 40 years ago continues to exist,'' Alarcon said.

He praised a measure before the U.S. Congress that would ease restrictions on shipments of food and medicine for Cuba.

Alarcon said the measure did not meet Cuba's demands that the entire embargo be lifted, but said he hoped it would ''lead to a radical change in the present policy.''

Since 1961, most U.S. business and travel to Cuba has been restricted by a U.S. embargo on the communist island nation. That ban was tightened in 1992 and again in 1996.

Showing the importance it attaches to improving ties with the United States, Cuba brought its ministers of economy, foreign trade and tourism to the conference, which began in Cancun, Mexico, on Thursday and was ending in Havana on Friday.

Other top political leaders were scheduled to attend a reception Friday night.

Though many of the conference participants take no political stand on the embargo, the conference organizers are members of Americans for Humanitarian Trade with Cuba, which supports easing the embargo on food and medicine.

While the U.S. government insists that such goods can now be shipped under Treasury Department licenses, many businesses say the requirements sharply restrict such trade.

Former U.S. Rep. Sam Gibbons of Florida told Alarcon that he was making his first visit to Cuba despite growing up in and serving Tampa, only about 180 miles away.

''I believe in engagement,'' he said. ''I believe it's time for a change'' in U.S. policy toward Cuba.

He urged Cuba to make some gestures or changes -- apparently referring to human rights or political issues -- so ''that we could begin to travel down the road together.''

Alarcon said Cuba was ready to talk ''in a more discrete atmosphere'' so long as the United States treated the island as an equal party.

''We haven't even said that before we can negotiate you have to end the embargo,'' he said.

The conference drew representatives from major drug, oil and transportation companies, as well as corporate attorneys and lobbyists. Cuban officials brought out local counterparts to speak with them about conditions and business opportunities in Cuba.

''We're here to take a look-see at the Cuban market, should it open up,'' said W. Bradford Gary, a board member of the Medical Device Manufacturers Association, which represents 160 U.S. companies.

William Lane, a Washington representative for Caterpillar, said the heavy equipment maker and other companies were so worried by the increasing use of U.S. trade sanctions that they formed a coalition called USA-Engage to fight them.

Lane, a speaker at the conference, said Caterpillar was badly hurt by earlier U.S. sanctions against the Soviet Union, when ''we turned over one of the biggest markets in the world to a competitor.''

Conference organizer Kirby Jones of Washington-based Alamar Associates said the gathering was authorized by the U.S. Treasury Department -- which enforces much of the embargo -- so long as the participants spend no money during the visit in which the Cuban government was host.