OPPOSITION JELLS. Strike poses biggest threat yet to Panama ruler. Military's approach deepens public rejection of Noriega

The 48-hour business strike that began in Panama City yesterday represents the most serious challenge by the civilian opposition to military strong man Gen. Manuel Antonio Noriega. Buoyed by the revelation last week that the United States had suspended military and economic aid to Panama, the Civic Crusade, a movement representing more than 100 business and professional groups, launched a shutdown of shops, factories, and offices. Panama's service-based economy and position as an international banking center depend on business confidence. And, with a foreign debt of more than $5 billion, it would not be able to survive with long-term instablity.

``I believe the pressure is going to become so great locally and internationally, that I wouldn't be surprised if these two days didn't end in Noriega leaving,'' said Urelio Barria, president of the Chamber of Commerce in an interview. ``There is no chance of dialogue with the military or the government unless the fundamental problem, General Noriega, is rectified.''

Barely two weeks ago, Mr. Barria had said it was not possible to oust Noriega in the immediate future. But the momentum of the protests has been carried by revulsion for the military's heavy-handed tactics during demonstrations on July 10. Scores of people arrested at the time emerged from their detention with stories of maltreatment. The Army's approach seems to have deepened public rejection of Noriega, and brought cohesion to the crusade that was absent a month ago.

On Sunday night, the government closed down three opposition newspapers and attacked the house of retired Col. Roberto D'iaz Herrera. It was his allegations of misconduct against General Noriega that first sparked popular unrest seven weeks ago.

The news that the US has suspended aid was followed by the publication of a letter from Noriega's immediate predecessor, Gen. Ruben Dario Paredes, which he addressed to ``the heart of the armed forces.'' In the letter, he identified Noriega as the sole cause of divisions within Panama. The perception that Noriega's authority has been seriously undermined is shared by diplomats.

``The era of Noriega is over no matter how long he holds on to his job,'' a Latin American diplomat says. But at the same time, Panamanian politics are so unpredictable and susceptible to all kinds of compromise, that few were predicting Noriega's dramatic downfall.

Yesterday's work stoppage appeared to be a success. Traffic flow was much less than normal in the city. Shops and offices were closed. Banks remained open as required by law, but many staff members did not turn up, and clients stayed away. Most important transactions had been carried out on Friday in anticipation of the work stoppage. However, the foreign banks' back offices where international business was conducted were operating, he said.

At lunchtime yesterday, the Army said it had detained 45 people at D'iaz's home following a seven-minute gun battle. Neighbors described how they heard explosions and saw helicopters hovering over D'iaz's house. Since he publicly stated allegations that Noriega had participated in electoral fraud, masterminded the murder of political opponents, and dealt in a network of corruption, D'iaz had been holed up in his mansion.