By JUAN O. TAMAYO Herald Staff Writer

Trying to enforce tough new rules on travel to Cuba, U.S. officials say they are ``reviewing'' a Washington firm's plans to take a group of American business people to Havana next month.

``We are looking intensely over their shoulder to make sure they meet the new regulations,'' one U.S. official said of Alamar Associates, a consulting firm on trade and business with Cuba.

Alamar's plans for a seminar on U.S.-Cuba business opportunities Sept. 9-12 call for one day of panel discussions in the Mexican resort of Cancun, followed by a one-day, one-night trip to Havana to meet with government and other officials.

The Havana stay would be legal if it is ``fully hosted'' -- if the costs are paid by someone not subject to U.S. laws, and the participants do not incur any other personal expenses while in Cuba that would violate the nearly four-decades-old U.S. embargo.

Alamar owner Kirby Jones said each participant will get a letter from the Cuban Ministry of Foreign Investment certifying it picked up the tab for all their hotel, food and transportation costs in Cuba.

But U.S. officials are suspicious because Jones is charging $3,250 per person for the seminar -- $1,200 more than a similar Alamar seminar in Cancun in March that included a one-day trip to Havana, without overnight lodging.

Jones claimed the higher price covers the cost of two nights' lodging at the Cancun Melia Hotel. Participants in the March seminar paid for their own hotel rooms, he said.

The $3,250 will cover the registration fee, lodging and meals in Cancun and the flight to and from Cuba, Alamar pamphlets noted. It doesn't include the cost of the flight from the U.S. to Cancun and back.

Until recently, Treasury officials seldom bothered checking U.S. residents who claimed to have been in Cuba on ``fully hosted'' visits. But an increase in illegal visits led officials to tighten regulations last March.

Anyone returning from an alleged ``fully hosted'' visit is now assumed to have violated the U.S. embargo, the new regulations say. They may be asked for written proof that someone else paid their expenses, and may be required to swear under oath that they spent no other money in Cuba.

``We don't have the power to stop them from going, but we can certainly take action when they come back,'' said one U.S. official. ``We may have questions when they return.''

Jones said he had met June 18 with officials of the Treasury branch that enforces the embargo on Cuba, the Office of Foreign Asset Control, and was ``satisfied, based on their comments, that the arrangements for the September conference satisfy all requirements.''

But a Treasury spokeswoman would not go that far. ``This is not an investigation, but Treasury is continuing to review the details of the trip,'' she said.

Alamar began arranging business seminars and trips to Cuba in 1974, and prospered as President Carter seemed headed toward improving relations with Havana from 1976 to 1980.

Business slowed when President Reagan was elected, but Jones says there's now a new push in the United States to lift virtually all U.S. economic sanctions against other countries, including Cuba.

``Today there are many more [U.S.] companies that are publicly participating in this debate,'' he told a news conference in Havana Monday. ``None of them is sufficiently powerful to change an entire policy, but collectively their weight is on the rise.''

The Clinton Administration has repeatedly vowed it would not change U.S. policy toward Cuba until the government adopts significant reforms, but it has made it easier to send humanitarian aid to Cubans.

Co-sponsoring Alamar's September seminar is USA Engage, a U.S. business coalition pressing for an end to U.S. economic sanctions against the authoritarian governments of Cuba, Burma, China and others.

Also listed as cosponsors: The National Foreign Trade Council, which favors lifting the embargo; Group B.M., an Israeli-owned firm managing a big part of Cuba's citrus production; and Havana Club International and Habanos, two joint Cuban-foreign ventures in the rum and cigar business.