Jacobo Timberman, the Argentine newspaper publisher whose year-long imprisonment has become a symbol of repression here and an important irritant in U.S. Argetine relations, will be freed from jail by the end of the North, and according to well-informed sources.

These sources said that Timberman's release was approved by Argentina's military junta on March 30 after it became clear that allegations linking Tmerman to leftist terrorist groups could not be sustaintiated and that the internation uproar caused by his continued deterntion harmful to Argentina.

Despite the lack of formal evidence against him, some segments of Argentina's armed forces have argued for Timberman's continued detention on the grounds that he is a symbol of the Jewish intellectuals whose liberal ideas the military say helped encourage urban terrorism here.

The decision to release Timberman is seen by some observers as a victory for more moderate military leaders such as president Jorge Videla, commander-in-chief of the army, and Adm. Emilio Massera, commandant of the navy, who have no great love for Timberman but who are said to believe that persons suspected of terrorist activity should not be detained once their innounce is established.

Sources here said that Timerman, once he is released from his cell at the federal police headquarters in Buenos Aires, will be placed under house arrest until a commission investigating his financial affairs has completed its work. Eventually it is expected that the junta will allow Timerman to leave Argentina, probably for Israel, where he has said he would go.

Marshall T. Meyer, who is Timerman's rabbi and who spoke with the newspaper publisher as recently as last week, said in an interview yesterday that "we are anxiously awaiting his immnient release to house arrest. It could happen today or next week."

Rabbi Meyer said he had no reason to think that any problems would occur that would delay Timerman's release beyond the end of April at the latest.

Government sources also said this week that Timerman's release was "certain" and that only a few formalities were left to be worked out.

The junta clearly hopes that Timerman's release will improve Argentina's image abroad, badly stained by the military's campaign against terrorists and their sympathizers.

The anti-terrorist drive has been conducted in a ruthless manner - similar to, but more effective than, the guerrilla war waged by leftist groups such as the Montoneros and the People's Revolutionary Army.Newspapers here estimated that more than 2,000 people have been killed by leftist terrorists since 1966 while human rights groups estimate that between 8,000 and 20,000 Argentines have disappeared since the military seized power two years ago.

It is believed that most of those listed as missing were taken by military squads. Many of those who disappeared in this way are thought to be dead. Prominent among those who have been arrested or have disappeared are many intellectuals, journalists, students with no apparent connectin to leftist terrorists.

The military blames these people for providing the intellectual framework or climate in which terrorism flourished. Timerman has come to symbolize - for both the Argentine military and the outside world - the intellectual targets of the anti-terrorist campaigns here.

The Carter administration has taken a special interest in the human rights situation in Argentina as well as in the Timerman case.President Carter personally expressed his concern about Timerman's fate when Videla was in Washington last Sepember for the Panama Canal treaty signings. The U.S. embassy in Buenos aires keeps abreast of the case.