SAN CRISTOBAL DE LAS CASAS, Mexico -- Mayan Indian guerrillas in southern Mexico have declared a unilateral and indefinite cease-fire in their year-old rebellion one day after the country's ruling and opposition parties agreed to negotiate sweeping political reforms.


The Zapatista National Liberation Army said the cease-fire began at midnight Monday and that rebel troops across the southern state of Chiapas had been ordered to take no offensive action as well as to begin defusing mines in rebel-controlled areas.


"It will be maintained as long as is necessary to achieve a stable and lasting truce," the Zapatista leadership said in a statement released to reporters here.


The move followed just two days after rebel chiefs met with Interior Minister Esteban Moctezuma.


The meeting was held in a Zapatista-held jungle town to clear the way for full-blown peace talks.


The cease-fire is an extension of a truce declared by rebel chiefs since Jan. 1, which was to expire Wednesday.


The Zapatistas took up arms on New Year's Day last year to demand major political reforms and autonomy for Mexico's many indigenous groups.


The truce comes after President Ernesto Zedillo of the ruling Institutional Revolutionary Party signed an accord with leaders of the three main opposition parties on reforms to strengthen their authority.


The accord will cede some of the ruling party's monopoly of power for the first time in 65 years of authoritarian rule.


In a dramatic ceremony Tuesday evening, Zedillo indicated the accord was a cornerstone of his promised new era of democracy. He predicted it would lead to more competitive, peaceful elections.


"Here and now, one era of history ends and another begins," Zedillo declared.


"This is the first step toward the democracy that Mexico demands. This is the first step toward building the unity that Mexico needs. Mexico here and now takes the first step toward a true democracy," He continued.


The agreement, signed at the presidential residence, came after days of negotiations among Zedillo, PRI leaders, heads of the Democratic Revolution Party, the National Action Party and the Workers Party.


The deal came just six weeks into a six-year term that Zedillo promised would institutionalize democracy in Mexico for the first time since 1929. It marked the first time in modern Mexico that a sitting president publicly appeared with the opposition to commit to resolving crises together.


Most opposition leaders shared Zedillo's enthusiasm for Tuesday's signing.


"This act is inscribed in our national history, however it develops, as an irreversible force for Mexico's transition toward democracy," declared PRD President Porfirio Munoz Ledo, adding, "or perhaps as the last push to save it from ingovernability and abdication."


There were few details in the two-page agreement but the accord made it clear that the ruling party had agreed to negotiate to level the playing field in future state elections and restructure the totalitarian city government in the nation's capital.


It is the home to a quarter of all Mexicans and its chief executive is appointed by the president.


(Reuters, LAT)