Nicaraguan Defense Minister Humberto Ortega has renewed his country's call for bilateral talks with Honduran officials to relieve recent border tensions, but he also insisted that his troops will continue to fire into Honduran territory as long as Nicaraguan rebels are permitted to operate from there.

The Hondurans have said that on May 10 the Nicaraguan Army fired artillery barrages that left one Honduran soldier dead and four injured near the hamlet of Arenales, about two miles inside Honduran territory. The hamlet is near Las Vegas, the largest Nicaraguan rebel camp in Honduras where several thousand rebels have been based.

Although the Nicaraguan Foreign Ministry had denied reports of the cross-border artillery fire, Ortega said at a press conference at a military school here Saturday that rebels had attacked from Honduran territory and there had followed an exchange of artillery fire across the border. He said it was also possible that Nicaraguan infantry had crossed the border during combat as was reported by the Hondurans.

He said he believed that recent rebel activity near the border was part of a plan by the Reagan administration to involve the Honduran Army directly in the conflict to spark a larger war and, eventually, justify U.S. intervention.

Ortega, brother of President Daniel Ortega, said despite that belief, his troops were under orders to return enemy fire from Honduras.

"We will respond to where the attack comes from," said Ortega. "We will never renounce the defense of even one inch of our territory."

He said members of his staff have been in contact with Honduran military authorities during the past week, but his offers to talk with the Honduran military commander, Gen. Walter Lopez, or set up a meeting of military commanders from the border region have been rejected.

During regional peace talks last week in Panama City, Nicaragua proposed that the peace-seeking Contadora group of four Latin American countries sponsor a commission that would oversee the disarming of the anti-Sandinista rebels, but Honduras turned down that proposal.

"We do not want incidents with Honduras," said Ortega, but he added, "undoubtedly, more of these hostile situations will be produced if Honduras does not control the mercenaries." He was referring to troops of the rebel Nicaraguan Democratic Force.

Nicaragua's regular Army, known as the Popular Sandinista Army, has driven many rebel forces out of Nicaragua and back across the border into Honduras during the past five months, which has caused the recent tensions, Ortega said.

Ortega said the Army's Irregular Warfare Battalions, consisting mainly of draftees, gained experience last year and are now doing well against the rebels. He said that 1,200 rebels have been killed this year. There is no way to confirm that figure independently.

He said this has forced the rebels to reduce the size of the groups in which they operate, from regional command forces of 750 men or more, down to task forces of 200 or even fewer. Sandinista military officials say this has made the contras, or counterrevolutionaries, less successful in attacking Sandinista agricultural co-ops and state farms, which are defended by volunteer militia units. Attacks on such farms, along with ambushes of military patrols and government vehicles, became the strategy of the contras last year and took a heavy toll on the Sandinista economy.

Ortega said recent rebel activity far from the border, such as attacks in the central province of Boaco last month, and an attack last week by Costa Rican-based rebels on Bluefields, the largest town on Nicaragua's Caribbean coast, were staged for propaganda reasons, to prove that the rebels still could strike deep inside Nicaragua. He said in both cases the rebels were repelled. Journalists were kept out of both areas after the attack, and independent information on the attacks was unavailable.

According to independent sources, rebels have been staging successful ambushes on important highways in the north central, northeastern and southeastern regions of the country during the past week.