Despite a boycott by Nicaragua, the foreign ministers of four other Central American countries met here today to discuss their specific objections to a peace treaty drafted by four Latin American countries known as the Contadora group.

A spokesman for the Honduran Foreign Ministry said the ministers had decided to meet again Saturday to draft a joint communique and a list of proposed changes. The revised draft reportedly is to be presented to the Contadora ministers when they next meet, most likely in November.

Controversy has surrounded the proposed treaty, officially known as the Contadora Act for Peace and Cooperation in Central America, since Nicaragua announced on Sept. 21 its willingness to sign it.

Less than a week earlier, the Honduran government had issued an official communique announcing it was "ready to assume its responsibilities . . . , which will culminate in the signing of the Contadora Act." On Sept. 19, Salvadoran President Jose Napoleon Duarte announced that he was "willing to sign," and he asked that a deadline of Oct. 15 be set for all the parties involved to indicate their willingness.

The treaty was negotiated by the foreign ministers of Mexico, Panama, Colombia and Venezuela, who first met for the purpose in 1982 on the small Panamanian island of Contadora. The group's principal aim is an agreement among all Central American countries to reduce foreign military influence, establish mechanisms for arms control and prevent countries from making or sponsoring war on each other.

The effort has received strong support from European social democrats and is endorsed officially by the Reagan administration as well.

Honduran Foreign Minister Edgardo Paz Barnica called for today's meeting when he spoke before the United Nations on Oct. 9. Nicaragua announced Tuesday that it would not attend, charging that the meeting was a U.S. attempt to torpedo the Contadora process. Alejandro Bendana, first secretary of the Nicaraguan Foreign Ministry, said, "This is a Latin American solution to a Latin American problem, and the United States just won't buy that."

Guatemala, which has tried to remain aloof from regional negotiations, is represented here only by a vice minister, Alfonso Alonso Lima.

In a brief opening speech, Paz Barnica said he hoped Nicaragua would "not absent itself in the future, but become a dynamic protagonist who understands that nothing is lost in working for the benefit of all."

In his equally brief reply, Costa Rican Foreign Minister Carlos Jose Gutierrez stressed that there is general agreement on the text of the treaty. "We are separated merely by procedural problems, norms for the execution, verification and control of the treaty ," he said.

"We want to sign the treaty," a Foreign Ministry spokesman said here today. "But we want to make sure that mechanisms for its implementation are agreed to at the same time."

Critics have charged that the draft leaves large loopholes for the Central American arms buildup to continue and does not propose specific supervision measures to ensure that the terms are met. However, when Nicaragua announced that it would sign the treaty, it precluded modifications.

It took many meetings, attended by officials both of the Contadora group and the Central American nations, to reach the general agreement represented by the proposed treaty. "We should remember that in March 1983 our problems were how to sit down around a table and if we could work in bilateral or multilateral meetings, and how an agenda could be drawn up," Gutierrez said.

It was widely believed in that period that Nicaragua would refuse to sign. Honduran press reports in the weeks preceding Nicaragua's announcement indicated that the Sandinistas were the principal obstacle to signing the treaty by Oct. 15.

Meeting separately in Madrid this week, the four Contadora countries announced willingness to consider modifications "as long as they do not upset the general balance" of the document.

West German ex-chancellor Willy Brandt, who has been promoting a negotiated solution to Central American conflicts, said in Mexico on Wednesday that "the Sandinistas told me they would be willing to accept a complementary document specifying with all due precision the different aspects of the treaty."

But if the Sandinistas are considering softening their position, other Central American countries are hardening theirs. "The Contadora group will solve nothing," Duarte said this week. "Because the Central American countries do not agree with the act [treaty], and no country has the right to impose its point of view on another."