U.S. special envoy to Central America, Richard Stone, abruptly headed home today after failing in his first effort to meet with leftist Salvadoran rebels.

The Salvadoran guerrilla movement blamed procedural disputes and a "propagandistic atmosphere" for the failure of the first attempt at dialogue that was to have taken place here yesterday.

Despite the propaganda charge aimed at Stone and the Salvadoran government, the guerrilla leadership also said in a communique issued here that it remains willing to seek further contacts. It called on Costa Rican President Luis Alberto Monge to pursue his attempts to set up the conversations.

As a result, it appeared that even after the initial setback here, the idea of discussions between Stone and the Salvadoran guerrilla movement would remain alive even as the three-year-old civil war goes on and the U.S.-supported government there moves toward elections set for December.

Stone flew in his Air Force jet back to San Salvador and then left for Washington, ending his second swing through Central America as the Reagan administration's special ambassador assigned to promote a negotiated settlement to the Salvadoran war. He declined to make a public assessment of what caused the failure. He has steadfastly refused comment throughout this tour.

The propaganda charges seemed to be an attempt by the rebel leaders to retaliate for Stone's strong criticism at the end of his first trip to the region last month. He accused the guerrillas then of violating sound diplomatic practice by publishing their invitation for the talks that were to begin here yesterday.

"Through the initiative of President Luis Alberto Monge, a meeting had been arranged for yesterday, July 9, between the special envoy of President Reagan, Richard Stone, and representatives of the FDR-FMLN," said today's rebel communique, using Spanish initials for the Democratic Revolutionary Front, the group's political arm, and the Farabundo Marti National Liberation Front, the umbrella guerrilla organization.

"Unfortunately, it was not possible to reach agreement over procedural aspects, which prevented the meeting from taking place. Also unhelpful to this was the propagandistic atmosphere that preceded it, in spite of the fact that it was designed to be private."

The rebel delegation, led by FDR chairman Guillermo Ungo, declined to specify what procedural wrangles prevented the discussions. Costa Rican leftists quoted by newspapers here said Ungo and his delegation were upset by a U.S. position that Stone was here only to relay Salvadoran government proposals and foster talks between the rebels and the government's Peace Commission to facilitate rebel participation in elections.

The rebels have insisted they cannot participate in elections organized by the present U.S.-backed government, which they consider to be a creature of Washington. Against that background, they view any contacts with Stone as a channel directly to the Reagan administration aimed at working out a peaceful resolution to the war that would include a rebel role in governing the country.

In an allusion to this stand, the communique said: "The FDR-FMLN reiterates its willingness for a dialogue and hopes that in the near future this can be achieved with Ambassador Richard Stone without prior conditions based on an open agenda and relying on an adequate framework."

Ruben Zamora, a member of the seven-member FDR political-diplomatic commission who frequently visits Washington, was part of the rebel team here with Ungo. Also on hand, the communique said, were Mario Aquinada Carranza and Jose Mario Lopez.

The rebel statement saluted Monge for his attempts to get a dialgue started, calling him a "highly qualified intermediary between Ambasador Stone and our fronts," and expressed gratitude for what it said were Monge's efforts to iron out the disagreements that prevented yesterday's scheduled talks from taking place.

"The delegation of the FDR-FMLN has demonstrated to President Monge the disposition of our fronts to continue working to achieve a dialogue as well as our desire that Mr. President maintain active his efforts in this regard," it said.

Costa Rican officials said Monge is eager to remain neutral in the Salvadoran conflict, while at the same time playing an active role in attempts to settle it. The FDR-FMLN has an unofficial representative here, for example, and the San Jose government has friendly relations with the United States and El Salvador.