Less than two months after the Dominican Republic's acceptance into a European trade program, some of that country's smaller Caribbean neighbors are questioning the Dominicans' true intentions.

At least five Caribbean banana-producing islands contend that the Dominican Republic is trying to crack the lucrative British banana market in violation of the Lome Convention.Dominican officials don't deny they have their eyes on Britain, but they say that in itself isn't a violation of Lome. All they promised, they said, was to refrain from seeking European financial assistance to develop their own banana industry.

Last December, the Dominican Republic and Haiti became the 67th and 68th beneficiary nations of Lome. Membership in the current agreement, known as Lome IV, took effect March 1. It gives the Dominican Republic alone access to more than $120 million in direct assistance from the European Community over the next five years.

"There is no doubt in anyone's mind" that Dominican officials misrepresented themselves to their Caribbean neighbors, argues Vin Evans, general manager of the 300-member Banana Export Co., which markets Jamaican bananas overseas.

"The Caribbean Banana Producers Association was asked by the Dominican Republic to support them in the Africa, Caribbean and Pacific group and in Lome, with the clear understanding they would not be competing with us on the market," he said. "Lo and behold, it turned out even while they were giving us this understanding, they were busily putting in place large acres of bananas to ship to the U.K. and Europe."

Mr. Evans said the Dominican Republic now has the capacity to grow 35,000 tons of bananas a year and plans to increase that capacity to 106,000 tons over the next few years. The Windward Islands Banana Growers Association, by

comparison, exported 233,000 tons of bananas to Britain in 1988 from its four member countries, Dominica, Grenada, St. Lucia and St. Vincent. Other large suppliers of bananas to Britain were Surinam (33,000 tons), Jamaica (32,000 tons) and Belize (26,000 tons).

Ministers of the Organization of Eastern Caribbean States, meeting in St. Lucia last week, expressed "grave concern" that the Dominicans' activities are "incompatible with and likely to undermine those negotiated commitments" made before the Dominicans entered Lome last fall.

Those activities center on La Cruz de Manzanillo, a large banana plantation located near Montecristi on the country's northern coast, close to the Haitian border. Phifes, a subsidiary of United Brands Ltd., recently showed interest in developing the plantation to export bananas to Britain.

Samuel Conde, a top private-sector official in Santo Domingo, conceded that "by Caribbean standards, the project is big," and that "anything that could remotely threaten the (Eastern Caribbean) market is going to be of concern."

But he insisted that his country never agreed to refrain from banana sales to any country, and he denied that the Dominican Republic has launched a ''banana war" against its smaller Caribbean neighbors.

"Our image in the Caribbean is that we're violating an agreement," he said. "But we haven't agreed not to export to Europe. It's irrational to say we're not going to export to a bona fide market."

Mr. Conde, who represents the Free Zone Association before a national

commission studying the impact of Lome on the Dominican economy, said the Dominican Republic signed protocols in three areas - rum, sugar and bananas - to overcome fears on the part of some smaller Eastern Caribbean states that already were receiving Lome benefits.

"Under Lome, the European Community will provide technical and financial assistance to develop the banana industry, from testing of soil through cultivation and packing," he said. "When the banana issue came up, we agreed not to pursue the benefits, not to use European aid to develop bananas."

He added that the Manzanillo banana plantation was no secret and that its existence shouldn't have surprised anybody.