MANAGUA, NICARAGUA, SEPT. 16 -- A top Sandinista official said today Nicaragua's leftist government is likely to allow the opposition daily La Prensa to reopen without censorship and is willing to talk with rebel field commanders to discuss details of a cease-fire to begin Nov. 7.

Meeting with foreign reporters, Commander Luis Carrion Cruz, who is deputy interior minister, added his comments to those of other Sandinista leaders who recently reaffirmed their commitment to comply with a peace plan signed in Guatemala Aug. 7 by the five Central American presidents.

President Daniel Ortega, in an address yesterday to the Central American ambassadors here, said the government will meet the terms of the accord even if Washington grants new military aid to the rebels, known as counterrevolutionaries or contras.

Renewed aid "would certainly be an obstacle to peace. But we are determined to confront the U.S. government's aggression against Central America by strengthening the unity among the region's nations . . . so in the end the United States will be left isolated," Ortega said.

The Guatemala accord calls for full democratic liberties and a general amnesty leading to a cease-fire and eventual end to guerrilla warfare in all five countries. All measures go into effect simultaneously in Nicaragua, Honduras, Costa Rica, Guatemala and El Salvador on Nov. 7.

To comply, the Sandinista government must ease political restrictions it has been reluctant to loosen in the past, and leaders of neighboring nations have expressed doubt that Nicaragua will meet the pact's requirements. Meanwhile, the Reagan administration has also questioned the plan and is pressing for $270 million in new aid for the contras.

Carrion, a graduate of Phillips Exeter Academy in New Hampshire, is one of nine comandantes who head the ruling Sandinista party and in practice run the government. The Interior Ministry is in charge of internal political intelligence.

Carrion described the peace plan as "the most severe blow to date to the Reagan administration's efforts to overthrow the Sandinista goverment by military means."

While reluctant to announce a timetable, Carrion said permission to reopen La Prensa was a measure the government could take before Nov. 7 to create a "constructive climate" for the accords. La Prensa, after publishing for four years under Interior Ministry censorship, was closed June 26, 1986, hours after the U.S. House of Representatives approved $100 million in contra aid.

Carrion added: "The political effect of reopening La Prensa under censorship would be weak. So I think it would come out uncensored."

The commander reiterated the Sandinistas' refusal to hold any talks with contra leaders. He said the government will declare a cease-fire unilaterally.

But Carrion said the government is prepared to seek "a form of communication" with middle-ranking contra field commanders inside Nicaragua to work out "the practical problems" of the halt in hostilities.

Carrion rejected demands by opposition human rights groups for the release of all political prisoners. The pact itself does not specify which, if any, prisoners must be freed under the general amnesty it calls for.

About 2,200 prisoners who served in the National Guard of the late dictator Anastasio Somoza would not be eligible for pardon, he said.CNN Reporter Ordered To Leave Panama Washington Post Foreign Service

MANAGUA, Nicaragua, Sept. 16 -- The Panamanian government today ordered Lucia Newman, correspondent for Cable News Network, to leave "as soon as possible."

In a telephone interview from Panama, Newman said an Interior Ministry official told her at midday her visa and press credentials were revoked. She said he warned that she could face "abuse and humiliation" if she stayed.

Newman is the second American reporter to be ordered out of Panama during a three-month-old political crisis. Reuter correspondent Tom Brown was expelled in July. Noriega also closed down all local opposition media.