The pro-government newspaper El Mercurio said yesterday that it had identified the picture of a man sought by a U.S. court in connection with the assassination of Chilean exile leader Orlando Letelier as a U.S. citizen who participated in right-wing commando actions against the leftist government of President Salvador Allende in 1973.

The U.S. government has asked Chile to produce two men for questioning about the 1976 car-bomb murder in Washington. El Mercurio printed wire photos of the two men on Saturday after the pictures were printed by The Washington Star on Friday.

One of the men pictured in The Star was identified as Juan Williams Rose. The U.S. government said Williams was a member of the Chilean armed forces.

A Chilean who said he knows the man pictured in El Mercurio corroborated the newspaper's account.

This source said he had known the man in the picture for several years, as Michael Vernon Townley, an American living in Chile since at least 1972 who boasted in conversations of his involvement in terrorist activities against Allende and of his membership in the extreme rightist group, Fatherland and Liberty.

The source said Townley's strange behavior and activities made him suspect that Townley was an agent of the U.S. Central Intelligence Agency.

El Mercurio's front page carried pictures side-by-side of the man said in Washington to be Williams and the man identified here as Townley. The two pictures seem to be of the same person.

Two weeks ago the State Department, in a procedure known as letters rogatory, asked the Chilean government to interrogate, using a list of sealed questions, two men identified as Williams, 28, and Alejandro Romeral Jara, 26.

The government responded that it would cooperate with the investigation, but a spokesman said the two names are not listed as members of the military, including the secret police, and there are no records of their existence in the files of the National Identification Service.

Reporters' inquiries here so far indicate that the names revealed in Washington are false. The U.S. embassy has said that two men using the names Williams and Romeral traveled to the United States in August 1976 on official Chilean passports and U.S. visas requested by the Chilean Foreign Ministry for official business.

El Mercurio, which is a major pillar of support to the government of President Agusto Pinochet, began last week to reproduce accounts from U.S. newspapers explaining the alleged involvement of Chilean officials in the Letelier murder. An editorial on Saturday called on the government to give a public explanation of why official passports and visa requests were provided for two men under false names.

The newspaper's recent coverage of the case is significantly different from its earlier reports, which attributed charges of government involvement in the murder to an international campaign against the military regime.

Other than to say the men do not exist in military and civilian files, the government has declined to coment on the men's mission to the United States.

U.S. investigators have said the two men traveled to the United States at least twice during 1976 and that one of them is believed to have made contact with someone responsible for the murders of Letelier and an associate, Ronni Karpen Moffitt, on Sheridan Circle.

The two died when a plastic bomb exploded under Letelier's car as they were on their way to work. Investigators have said they do not know how the bomb was triggered but they have speculated that it could have been electronically.

Townley, according to the source who knew him, worked during 1974 and 1975 in a Santiago garage as highly specialized ignition and tuneup man. The source said he once saw Townley's American passport. Although the picture was that of his acquaintance, he said, the passport carried a different name, which he said he could not recall.

The Chilean who knows Townley said he bragged that he was a member of Fatherland and Liberty and rad participated in a commando raid on a television station in the southern port city of Concepcion in mid-1973 in which a night watchman was killed.

In that incident the raiders successfully disconnected and destroyed an electronic jamming device that had been installed by Allende government officials to prevent the station from going on the air as part of an opposition network.

El Mercurio published a picture yesterday of the June 9, 1973, front page of a now defunct newspaper, Puro Chile, in which Townley's picture appeared with a story accusing him of being the "Concepcion murderer" and alleging that he was a CIA agent who had operated in Chile since 1968. Puro Chile was known as a sensationalist newspaper. It was published by members of the Communist Party, which was then a coalition partner in Allende's government.

Fatherland and Liberty participated in an abortive coup attempt against Allende in conjunction with a tank regiment of the Chilean army several months before the successful Sept. 11, 1973 coup by the three branches of the armed forces and the national police.

After the coup, leaders said the organization had been disbanded, but there were numerous reports that its members were recruited by the army as agents of the secret police, the Directorate of National Intelligence (DINA).

Sources in Washington have said Williams and Romeral are believed to have been working as DINA agents when they went to the United States. The government later dissolved DINA and created a substitute organization. Many DINA agents reportedly were fired at that time.

According to the man who said he knew him, Townley also had talked about his operating a clandestine radio transmitter from his car in October 1972 to broadcast against Allende during a national strike. He said he last saw Townley about seven weeks ago in Santiago and learned that he no longer worked at the garage.

"My impression has always been that guy has something to do with the CIA. He had two U.S. passports; he was a foreigner involved in subversive activities in Chile with extreme rightist groups. Everything about him was mysterious and he made multiple trips abroad," the Chilean said.

El Mercurio quoted a woman who said she was agood friend of Townley as saying that she "understood" that he was connected with Fatherland and Liberty, but that she had not seen him since he fled Chile by crossing the Andes mountains in 1973. Some of the details of the woman's story contradicted the El Mercurio account and a description of him given by the man who knew him.