South American leaders have begun a series of informal contacts in an unusual display of summitry aimed at overcoming common debt problems and securing newly elected democratic administrations.

In a show of high-level fraternity virtually absent for several years on this southern continent, the chief executives have taken to telephoning one another frequently to exchange views and experiences and to coordinate strategies. The heads of state have also used such customarily ceremonial gatherings as a string of recent presidential inaugurations to meet in private about shared concerns.

The ease with which the leaders, several of whom assumed office only this year, are communicating has impressed aides and analysts. This phenomenon is widely seen as likely to contribute to the strengthening of democratic institutions in South America.

While acknowledging that behind-the-scenes exchanges are occurring with growing frequency, officials caution against expecting the contacts to lead any time soon to the establishment of any new formal structure. They note that past efforts to unify the region have foundered on national egos and historical antagonisms among South America's 13 diverse states.

Nonetheless, the new pattern of presidential consultations is an intriguing aspect of the return of electoral politics to South America. These analysts anticipate it will strengthen regional solidarity both in dealings with foreign banks and governments and in the modeling of new domestic systems.

"It is very positive for Latin America to have the beginning of a presidential diplomacy," remarked Peruvian President Alan Garcia in an interview in New York last week. "We are still not gathering the fruits from that, but I do believe we are sowing something."

Compelling the Latin leaders to search out one another are a number of mutual problems. The most overwhelming is the debt owed northern banks and governments. With growing force in recent months, the southern nations have made the point that their economies can no longer afford the policies of austerity adopted previously at the insistence of creditors and the International Monetary Fund. They now demand fresh loans and relief from crippling interest payments in order to return to economic growth.

After Mexico's moratorium on debt payments in 1982, the debt issue was blurred during a country-by-country approach to managing the crisis favored by the banks and acceded to by the debtor states. Now, out of desperation at still being saddled with the problem, they appear inclined to take a more coordinated approach in seeking a more global solution.

The extent of Latin cooperation in this area still falls well short of a debtors' cartel. But the added dimension of presidential contacts seems to have carried the countries beyond the symbolic unity represented by the Cartagena group, the conference of 11 Latin debtor states established last year as a system for consulting on foreign debt payments and promoting changes in the international financial system.

"Before beginning my talks with the banks," Uruguayan President Julio Sanguinetti said in an interview in New York last week after completing a new rescheduling agreement, "I spoke with other leaders. Their points of view were very useful, especially that of President Jaime Lusinchi of Venezuela."

Sanguinetti, who took office in May as Uruguay's first democratically elected president after 12 years of military rule, said he sometimes speaks on the phone two or three times a week with other South American leaders.

"Last week I talked to Brazilian President Jose Sarney about some trade matters," he recalled. "The previous week I talked to Argentine President Raul Alfonsin about some small topics, political topics, involving what Alfonsin's Radical party would do on some international matters. Likewise with President Belisario Betancur of Colombia. The moment we hear of a problem in Central America, we get in touch with him and other friends up there to see what they think of it.

"It has never happened in our history that we could talk fluidly and frequently over the phone with the heads of neighboring states," added Sanguinetti, clearly pleased by the development. "It often happens without any particular issue to discuss."

Contributing to the inclination now of presidents to pick up the phone and dial one another is a sense of common cause in restoring democratic order in the region.

"There is more familiarity among the politicians because of their similar struggles against the military regimes that governed before and the difficulties they share in building democracy," said Oscar Camilion, an Argentine ex-foreign minister now practicing law in Buenos Aires.

In the past two years, new governments have taken power in Argentina and Brazil -- South America's largest states -- as well as in Uruguay and Bolivia. Military or dictatorial rule continues only in Chile, Paraguay and Suriname. In Panama, generally included in the South American bloc, the military just forced out an elected president, but new governments in Venezuela, Ecuador and Peru received their power from democratically elected predecessors.

The new presidents appear to value personal contacts with fellow heads of state as a way of nurturing trust, overcoming a lingering sense of provincialism and expanding their own knowledge and experience.

Riordan Roett, director of the Latin American program at The Johns Hopkins School of Advanced International Studies in Washington, said: "The increasing conversations between democratic leaders in Latin America have not been seen for two decades. In a sense, the politicians are in a process of finding their own identities."

Garcia, who at 36 is the youngest of the group and the most outspoken, has urged making the presidential contacts more formal. In his inaugural speech in July, the Peruvian suggested a meeting of all Latin American leaders -- rather than of the smaller South American grouping -- in Panama. The idea, however, was coolly received by the others.

The Latin American Free Trade Association, formed in the 1960s with hopes of becoming a sort of Western Hemisphere version of the European Common Market, died in obscurity in 1980. It has been replaced by the feeble Latin American Integration Association. The Andean Pact, a similar effort at a smaller regional economic integration, also faltered.

The Organization of American States labors under a credibility crisis due in part to its heavy dependence on U.S. funding. The U.N. Economic Commission for Latin America and the Caribbean amounts to little more than a source of useful statistics and information about the region.