Prime Minister Shimon Peres has ordered a halt to an attempt to close an East Jerusalem Arab news agency and weekly magazine by Israel's Interior Ministry and the Israeli Army.

Informed government sources confirmed a report by Israeli radio today that Peres had personally intervened in the case against the Palestine Press Service, a key source of information on developments in the Israeli-occupied West Bank and Gaza Strip.

The sources said a hearing in the case would go forward as scheduled on Monday, giving both sides a chance to make their arguments, but that Peres had already decided that the proceeding against the news agency should be dropped after the hearing.

There was no official comment or explanation of the decision from Peres' office.

The Interior Ministry and the Army's central command accused the Palestine Press Service two weeks ago of being "guided and financed" by the main Fatah wing of the Palestine Liberation Organization and threatened to revoke the agency's license to operate. The news agency's coowners, Raymonda Tawil, a prominent Palestinian writer, and Ibrahim Karaeen were ordered to appear at the hearing Monday to answer the charges.

Peres' decision in the case was watched closely here for indications of the new national unity government's initial policies toward Palestinian organizations in East Jerusalem and the West Bank. The threat to close the news agency was initiated under the previous Likud bloc government.

"It's a very nice step in the right direction," Karaeen said today. "We hope it will be followed by other steps on newspapers in general -- a lifting of the heavy censorship."

Peres is the head of Israel's Labor party, which has generally pledged to impose less severe policies in the West Bank and Gaza than the Likud bloc. According to reports in the Israeli press, Peres, who leaves here Saturday night for a meeting with President Reagan in Washington, is also considering other steps to ease regulations in the occupied territories.

Secretary of State George P. Shultz has urged the Israeli government to take steps in order to improve the "quality of life" in the West Bank and Gaza.

Tawil is a widely known Palestinian activist and the news agency she founded in 1977 a well established East Jerusalem institution. The threat to close the news agency was protested by a number of Israelis, including several journalists.

The news agency supplies information on West Bank and Gaza developments to foreign and Israeli journalists and diplomats stationed here.