BUENOS AIRES (AFP)--Bolivian President Evo Morales and Paraguayan President Fernando Lugo signed a historic accord here Monday, ending a boundary dispute that led to a catastrophic war in the last century.

In a solemn ceremony chaired by Argentine leader Cristina Kirchner, both presidents agreed that the dispute over the Chaco region - where a war between 1932 and 1935 left more than 100,000 people dead - was brought on by foreign interests.

The armed conflict "came from outside, driven by transnational corporations competing for our natural resources," said Morales after signing the agreement, which agreed to the terms of the Bolivian-Paraguayan Boundary Demarcation Commission.

"These are new times of peace, friendship and fraternity between the peoples of South America," he added.

The Western companies seeking energy riches in the vast region at the continent's heart were U.S. Standard Oil, backed by Bolivia, and the Anglo-Dutch Shell Oil company, supported by Paraguay.

Lugo expressed hope that the two nation's bountiful natural resources could in the future "be developed and used by both countries without any foreign intervention."

He said that "never again" should the two countries let outside influences promote distrust and suspicion that would "poison our relations."

At the end of the ceremony, held at the palacial Casa Rosada in Buenos Aires, Kirchner also alluded to the interests of powerful oil companies that had shaped the region.

The war between Bolivia and Paraguay "smelt of oil, as did many wars in those days and now," she said.