The heads of Latin American and Caribbean nations are meeting in Santiago, Chile, today for an annual summit amid fears that the global trade talks so vital to their economic development are on the verge of collapse.

Although aid to Cuba and vio- lence in Haiti are expected to dominate newspaper headlines, the leaders will be discussing a common response to the increasing likelihood that the Uruguay Round of global trade talks may fail.Equally distressing and also expected to be high on the agenda for the leaders is the dubious fate of the proposed North American free-trade agreement that would bind Mexico, Canada and the United States into a single free market.

The Uruguay Round of the General Agreement on Tariffs and Trade has been stalled in large part by French recalcitrance on reducing farm subsidies. The round, which began in 1986, must be completed in December.

Many analysts fear protectionism and trade wars would result in the event of a breakdown.

Latin American and Caribbean nations say new global trading rules that would open the doors to commerce further - the goal of the Uruguay Round - are being held hostage by bickering between the United States, Japan and the European Community.

"For us, the important themes are regional integration and conclusion of the Uruguay Round of the GATT," Julio de la Fuente, who heads commercial programs for Chile's embassy in Mexico City, said in an interview.

The annual meeting of the Grupo de Rio - as the summit is known - has an informal agenda. But Mr. de la Fuente said he expected the stalled global trade talks to be a subject of urgency for the presidents.

Protectionism could not come at a worse time as Latin American and Caribbean nations sell off state-owned enterprises, reduce tariff barriers and forge regional trade pacts - often at great political and social cost - in hopes of attracting foreign investment for their export-oriented industries.

What good would all that do if markets worldwide remain inaccessible, the leaders say.

Mexican President Carlos Salinas de Gortari called for a rapid conclusion of the Uruguay Round during a news conference Tuesday in Trinidad and Tobago, where he met with his Colombian and Venezuelan counterparts to announce tentative agreement on a trilateral free-trade zone.

"I must say that we have concerns about the Uruguay Round . . . that we hope can be resolved and finished with positively and quickly," Mr. Salinas told reporters.

Also expected to be discussed at the Grupo de Rio summit is the Nafta and its uphill battle in the U.S. Congress.

At the conclusion of this week's so-called Group of 3 meeting in Trinidad and Tobago, Colombian President Cesar Gaviria said that other regional free- trade initiatives in the Americas could unravel if the Nafta is defeated.

Those initiatives include the Andean Pact, comprising Venezuela, Colombia, Ecuador, Peru, Bolivia and Chile; the Caribbean Community (Caricom), comprising Antigua and Barbuda, Bahamas, Barbados, Belize, Dominica, Grenada, Guyana, Jamaica, Montserrat, St. Kitts-Nevis, St. Vincent and the Grenadines and Trinidad and Tobago; the Central American Common Market of Costa Rica, Panama, Honduras, Guatemala, El Salvador and Nicaragua; the Group of 3, comprising Mexico, Colombia and Venezuela; and Mercosur, comprising Argentina, Brazil, Paraguay and Uruguay.

"We are convinced that if we miss this opportunity, many years - even decades - will pass before we can return to thinking about a climate that can provide an opportunity that is given in this occasion with Nafta," Mr. Gaviria said.