Venezuelan President Hugo Chavez and Bolivian President Evo Morales arrived on Friday. They planned to sign the accord with Cuban President Fidel Castro on Saturday and participate in an evening rally in Havana's Revolution Square.

"This meeting is a great meeting of three generations, of three revolutions," Morales, who was elected in December, said upon arrival.

Castro came to power in a 1959 communist revolution, and Chavez first won election in 1998 to lead what he calls a "Bolivarian revolution."

The three-way summit takes place on the first anniversary of a comprehensive political, social and economic integration agreement between Cuba and Venezuela, dubbed the Bolivarian Alternative for the Americas (ALBA), after South American independence hero Simon Bolivar.

The accord gives Cuba preferential financing for Venezuelan oil and payment for more than 20,000 Cuban doctors and other professionals working in Venezuela. It has helped Cuba emerge from the economic crisis that followed the demise of the Soviet Union, its former benefactor .

Bolivia, by joining the pact, will gain access to Venezuelan energy resources and financing, Cuban doctors, teachers and other professionals, and markets for products such as soy.

"ALBA has worked very well for both Cuba and Venezuela, and Bolivia's joining can only improve it by adding another dimension," Cuban economist Omar Everleny said.

LATIN AMERICA SPLIT ON FUTURE

Nicaraguan Sandinista revolutionary Daniel Ortega, who held power in the 1980s and is a leading candidate in a presidential election this November, was also in Havana, apparently as an observer.

Chavez and Castro cast ALBA as a contrast to a faltering U.S. plan for a "Free Trade Area of the Americas," which they charge is a U.S. bid to reinforce its domination of Latin America. The message has resonated in a region where free-market policies have failed to alleviate chronic poverty.

"Until this year, Castro and Chavez seemed doomed to remain a two-man club. The addition of Morales dramatically changes this equation," said Daniel Erikson, Caribbean programs director at the Inter-American Dialogue, a Washington policy group.

"By adding a country with significant gas reserves that are increasingly under government control, Bolivia's membership expands the economic potential of ALBA, which already includes Venezuela's huge oil reserves," Erikson said.

Latin America is increasingly divided on how to form an economic bloc that can compete in the global economy.

Venezuela and Bolivia threatened this month to the leave a five-member Andean Community of Nations because members Colombia, Peru have signed U.S.-sponsored free-trade agreements. Ecuador is considering a similar pact with Washington.

Nine Latin American countries, including Mexico and Chile, have signed free-trade agreements with Washington. Others, such as all-important Brazil and Argentina, have refused, while also keeping their distance from Venezuela's ALBA.

"It remains to be seen how far this alternative economic model will take hold in the hemisphere. Most countries are not about to adopt restricted, selective policies toward foreign investment or turn toward state direction of the economy," said Phil Peters, vice president of the Lexington Institute, a conservative U.S. think tank.