While Nicaragua's junta government is closeted in temporary offices in the city's old Central Bank building, making plans and appointing administrators, a small, uniformed figure has emerged as the most visible member of the new regime.

Interior Minister Tomas Borge spends his days trouble-shooting, smoothing chaos and settling disagreements ranging from workers' squabbles to urban skirmishes between Sandinista soldiers and terrorist renegades from the surrendered National Guard.

To his guerrilla followers, Borge is known as "El Viejo" - the Old One. Nearing 50, he is the only remaining member of the small guerrilla band that became the Sandinista National Liberation Front in the early 1960s.

The recognized leader of the Sandinista Prolonged Popular War Faction, he has attracted a following of militant students who say they believe in traditional guerrilla warfare against the "forces of exploitation."

U.S. officials consider Borge one of the most radical Scandinistas because of his lengthy fight against the Somoza dynasty, his cordial relationship with Fidel Castro, and his strident denunciation of imperialism from the north. They are concerned that the ministry he operates has control over national security and police forces.

To journalists here, who find him ever ready to conduct an impromptu press conference and a dependable source of both information and bon mots, Borge is known as "the Chinaman" Small in stature, with slightly slanted eyes, he dresses in an olive-drab uniform topped with a Chinese Communist-style cap carrying a single star.

Borge walks with a slight limp, which he attributes to two recent years in Anastasio Somoza's prison. He was released and flown to Cuba last August as part of a ransom for more than 1,000 hostages held by the Sandinistas in the National Palace.

Like Castro, Borge trained as a lawyer. Born in Leon, he was jailed for two years as a student activitist following in the assassination of Somoza's father in 1956 and again in 1976 after a shootout with the National Guard.

But while his background, style and ideology resembles the Cuban leader, Borge so far has conducted himself as a model representative of the new coalition government. His comments on a variety of subjects over the past several days have been directed toward soothing, rather than accentuating, its differences.

Among his comments:

On the possibility of divisions between the guerrilla-appointed junta and the Sandinista leadership - "Some of us have distinct ideologies, but we are working together for the reconstruction of the country. The decisions made here correspond to the government's plan. If we have designated a government, then we have to be respectful of the decisions it makes. The program of the junta is as clear as a drop of water on a summer day."

On concern over private property - "That's one thing we want to guarantee. Private property in this country will be respected. The only thing the revolutionary state has taken over to adminster is the property of Somoza and his henchmen. The industrialists can keep calm. Contrary to what they might think, we aren't hostile to them, what we want to do is help them."

On Somoza - "We will ask for his extradition. We are not going to send anybody to kill him; that would be a violation of U.S. law. We are very respectful of the laws of other countries."

On possible surprises the Nicaraguan revolution has in store - "If I told you, they wouldn't be surprises."

A revealing indication of how Nicaragua may be run in the near future came yesterday, when several hundred employes of the Intercontinental Hotel called a "people's power" meeting and asked for Borge to be present.

In dispute was the hotel's future management. Most employes, including the managers, fled during the war when the hotel was occupied primarily by Somoza officials and soliers. Control of the hotel and remaining employes was taken over by personel director Norman Balario, a Somoza supporter who was openly abusive to underlyings and enjoyed waving a pearl-handled revolver around the lobby.

Most of the hotel's 300 employes obeyed a junta call for everyone to return to work yesterday. Rather than Balario, however, they wanted as their manager chief hotel engineer Carlos Pereira. Also in the running was Dr. Tapia Mercado, a Nicaraguan whom the overseas owners of the hotel had designated.

Borge entered the volatile meeting to employes' cheers and chants of "Long live the Sandinista Front."

"Where is this Balaro?" Borge asked. "Somebody go get him." Balario was brought before the meeting and, on Borge's orders, taken away "for investigation."

"Now," he said, "abuses here and other companies are over forever. The first thing you have to do is organize yourselves to protect the rights of the workers by defending your own interest, electing your own leaders."

But, he warned, "your service must be more efficient than ever, to the tourists, better than ever."

"We know Dr. Tapia had associations with the Somoza government," Borge said.

"I think he's basically an honest man and we owe him the opportunity, as we owe everyone the opporunity, to prove his owrth. I know he's going to act with respect for the workers, with affection for the class that has sacrificed so much." Pereria, the engineer, would help Tapia and serve as laiaison to the workers, Borge said.

The employes seemed satisfied with the decision. CAPTION: Picture, Interior Minister Tomas Borge is accessible to press. AP