ARGENTINA'S PRESIDENT OPENED A SOUTH AMERICAN TRADE SUMMIT FRIDAY WITH A CALL FOR GREATER POLITICAL AND ECONOMIC INTEGRATION IN THE REGION, DPA REPORTED. THE SUMMIT OF THE MERCOSUR TRADE ALLIANCE BROUGHT TOGETHER PRESIDENTS OF MEMBER COUNTRIES BRAZIL, PARAGUAY, URUGUAY AND NEWCOMER VENEZUELA. ALSO TAKING PART WERE THE LEADERS OF CUBA - FIDEL CASTRO AS AN INVITED GUEST - BOLIVIA AND CHILE. ARGENTINE PRESIDENT NESTOR KIRCHNER WELCOMED VENEZUELA, THE FIRST COUNTRY TO JOIN THE PACT SINCE ITS CREATION IN 1991. HE SAID IT "SHOWS THE STRENGTH OF THE PROCESS" AND "WILL MAKE THE BLOC MORE DYNAMIC." KIRCHNER REAFFIRMED MERCOSUR'S COMMITMENT TO THE CONSTRUCTION OF A CONTINENTAL GAS PIPELINE LINKING VENEZUELA AND SOUTHERN ARGENTINA. "IT WILL BE A SOLID PLATFORM FOR INTEGRATION, NOT ONLY IN THE FIELD OF ENERGY, BUT ALSO AT THE POLITICAL AND SOCIAL LEVEL," HE SAID. MORE BROADLY, KIRCHNER URGED MERCOSUR COUNTRIES TO INJECT FRESH MOMENTUM INTO THE ALLIANCE, WHICH HAS LAGGED IN BREAKING DOWN INTERNAL TRADE BARRIERS.