President Clinton on Wednesday kept Cuba off the list of nations that are major transit points for U.S.-bound narcotics, saying the amount of drugs passing through the island has dropped this year.

Congressional conservatives who had demanded that Clinton add Cuba to the ``majors list immediately assailed the decision and pointed out that his own aides reported in May that drug traffic through Cuba was up last year.

The ``majors list does not imply any sanction of the nation listed but requires U.S. presidents to certify each March whether the country's government is cooperating in the war on drugs, and it can affect U.S. counter-narcotics aid.

In a letter to Congress, Clinton said Cuba is an ``area of concern, but evidence showed that the flow of U.S.-bound drugs through Cuban airspace and waters had ``decreased significantly since last year.

The letter accepted the conservatives' argument that any drug shipments passing ``through Cuban airspace and waters should be considered when drafting the ``majors list. Some administration officials had argued for months that shipments that did not touch land should not be counted.

But the letter also raised a question about the word ``significant.

The law that created the list requires the inclusion of transit points for ``significant quantities of drugs, but does not define ``significant.

Clinton also wrote that intelligence data showed that a 7.2-ton shipment of cocaine seized in Colombia on its way to Cuba last year was eventually bound for Spain. Congressional conservatives suspect it would have gone from Cuba to the United States -- and noted the volume was enough to land Cuba on the list.

Rep. Benjamin Gilman, R-N.Y., chairman of the House International Relations Committee, blasted the decision and said he would hold a hearing soon to consider legislation that would force Cuba's inclusion on the list.

``Clear evidence shows that massive amounts of illegal narcotics bound for the United States transit the Cuban land mass, Cuban airspace and Cuban waters, Gilman said.

Aides noted that Clinton's drug czar, Barry McCaffrey, in a May 27 letter to Congress, wrote that ``intelligence and law enforcement communities report that detected drug overflights of Cuba, although still not as numerous as in other parts of the Caribbean, increased by almost 50 percent last year.

Listed as major production or transit points were Afghanistan, Bahamas, Bolivia, Brazil, Burma, Cambodia, China, Colombia, Dominican Republic, Ecuador, Guatemala, Haiti, Hong Kong, India, Jamaica, Laos, Mexico, Nigeria, Pakistan, Panama, Paraguay, Peru, Taiwan, Thailand, Venezuela and Vietnam.