August 13, 1983

As most of midtown Manhattan's garment district remained blacked out for a third day yesterday, the Consolidated Edison Company held out the hope that full power might be restored as early as this morning. A Con Edison spokesman, Herbert Hadad, reported last night that by 7:30 P.M. about 60 percent of the necessary cable splicing had been done. ''The work has progressed well, better than anticipated,'' he said. Con Edison had earlier said that service might not be restored until Monday.

Libyan planes were reported today to have attacked the remote outpost of Oum Chalouba in what seemed to be a prelude to further advances into Chad. According to reports from Western and Chadian sources, the Libyan planes, which played a major role in the assault on Wednesday against the northern oasis of Faya-Largeau, were in action Thursday and today. A Government force of 1,000 soldiers captured Oum Chalouba from the rebels just two days ago. Oum Chalouba is about 180 miles southeast of Faya-Largeau on the road to Abeche, the most important town in eastern Chad.

Agriculture Secretary John R. Block and Labor Secretary Raymond J. Donovan are in sharp disagreement over the wage rates to be paid to aliens who come legally to this country to harvest fruit, vegetables and other crops. Mr. Block complained, in a letter to Mr. Donovan, that new wage rates set by the Labor Department were too high. The proposed increase, over 30 percent in some states, is ''inflationary and unreasonable,'' Mr. Block said. Labor Department officials, defending the new wage rates, said lower rates would adversely affect American workers by depressing their wages.

At precisely 9:45 A.M., LeDeane Tummings turned on the public-address system in Gimbels. ''Base to all employees,'' he said. ''Miracle on 32d Street. The store is open for business. Have a nice day.'' When the announcement was made, Teddy Zambounis, Gimbels's chief electrician, was sitting at the counter of the store's slightly stale- smelling restaurant eating fried eggs and bacon.

Government officials, reacting to the apparent desire of the 16-year-old son of a Soviet diplomat to stay in the United States, tightened security at points of exit today and said they would insist on interviewing the youth before he is returned to the Soviet Union. ''We are not going to let him out without interviewing him,'' a State Department official said. The affair, first viewed as a missing- persons case and then transformed into an incident with international implications, set in motion an exchange of diplomatic notes and prompted a series of alerts to Immigration and Naturalization Service officers at border stations and points of exit around the nation. ''Things are buttoned up,'' said a State Department official, describing that action. Officials would not give further details on the tightened security measures.