President Jose Napoleon Duarte, facing growing disenchantment from workers and peasants, called today for the renewal of peace talks with leftist guerrillas fighting to overthrow his U.S.-backed government.

In a concession to the rebels, Duarte said the meeting could be held inside this country in late July or August, but he made it clear that he wanted to discuss their putting down arms and joining electoral politics.

Farabundo Marti National Liberation Front guerrillas and their allies, exiled politicians of the Revolutionary Democratic Front, could not be reached for immediate comment on the proposed talks. Duarte's government and the guerrillas met twice in late 1984 but no results were announced. Since then they have been unable to agree on terms for a third meeting.

The rebels also have pressed for further talks. Representatives of both sides met in Peru in April but they indicated no progress toward a negotiating session.

Duarte made the surprise announcement at the end of a two-hour speech to the National Assembly marking the second anniversary of his presidency. He asked Msgr. Arturo Rivera y Damas, Roman Catholic archbishop of San Salvador, to make arrangements for a meeting with the guerrillas. The church prepared the earlier talks.

"I want to end the war," Duarte said. "I make this new invitation expressing the sentiment and the will of the people who want those in arms to incorporate into the democratic process -- to put down their arms and end this war that has caused our country so much pain and blood."

Unionized workers and farmers have begun turning out this year for street demonstrations protesting Duarte's economic austerity program and calling for dialogue with the guerrillas.

In January, Duarte implemented an unpopular economic austerity plan supported by the United States that included currency devaluation, limits on imports and price increases. A recent government poll showed that only 24 percent of those surveyed supported Duarte's Christian Democratic administration, a percentage larger than that favoring any other political party but far below the 40 percent who said they either did not care or did not care to answer.

During the speech, Duarte outlined the achievements of his first two years in office, including construction of housing and bridges and increases in public and private employment. But economists say about half of the work force is still unemployed or laboring in marginal jobs.

Right-wing opposition legislators boycotted the speech. Duarte, irked by this attempt to embarrass him, lashed back, comparing the absent legislators to leftist guerrillas throughout Latin America.

While Duarte spoke, 60 members of a human rights group occupied the capital's cathedral to demand the release of nine human rights activists arrested last month, United Press International reported.