U.N. Chief Delegates Air Strike Authority : Bosnia: Secretary general’s representative on the scene has authority to call up warplanes.

In a move that appeared to intensify the threat against the Serbs in the hills around Sarajevo, U.N. Secretary General Boutros Boutros-Ghali on Friday delegated his authority to order NATO air strikes in Bosnia-Herzegovina to the ranking U.N. official on the scene.

The delegation of authority to Yasushi Akashi of Japan, the secretary general’s special representative in the former Yugoslav federation, was clearly designed to speed up the process for reaching any decision to send U.S. and European planes against Bosnian Serb artillery batteries.

In his announcement, made in a letter to the Security Council, Boutros-Ghali also said he had instructed Akashi to meet with U.N. and NATO military commanders “to finalize . . . detailed procedures for the initiation and conduct of air strikes.”

This made clear that a decision by Akashi to order the strikes would be heavily influenced by Adm. Jeremy M. Boorda of the United States, the commander of North Atlantic Treaty Organization forces in southern Europe, and by Gen. Jean Cot of France, the commander of the U.N. peacekeeping forces in the former Yugoslav federation.

Cot has complained often that it would take too long for the use of NATO air power to be approved if the decision had to come from New York.

This complaint prompted Britain and France to persuade Boutros-Ghali a few weeks ago to delegate authority to Akashi for the calling of close air support to protect U.N. peacekeepers if attacked at the Bosnian towns of Srebrenica and Tuzla.

U.S. officials said they did not anticipate that Akashi would act any differently than Boutros-Ghali if the need came to call for air strikes.

“We are fully confident that if the Serbs start shelling Sarajevo from the hills around the city, the secretary general or his representative will order air strikes,” a U.S. official said.

In a special meeting Wednesday, the NATO council gave the Serbs 10 days to either withdraw their heavy weapons from the hills around Sarajevo or put them under U.N. control.

NATO warned that it would, at the request of the secretary general, send planes against any artillery or mortar positions firing on Sarajevo even before the deadline expired and against any such position still in place after the deadline.

In his letter to the Security Council, Boutros-Ghali, still hopeful for a peaceful settlement, also said he had instructed Akashi and the U.N. military commanders to try to negotiate an agreement for a cease-fire in Sarajevo, a withdrawal of Bosnian Serb weapons from the area or their transfer to U.N. control, and a transfer of Bosnian Muslim weapons to U.N. control.

Such an agreement had already been worked out by Lt. Gen. Michael Rose of Britain, the commander of U.N. forces in Sarajevo, but it is still uncertain whether it will hold.

The 63-year-old Akashi, a veteran Japanese diplomat and U.N. bureaucrat, headed the U.N. peacekeeping operation in Cambodia that led to successful elections last year. He took over the operation in the former Yugoslav federation Jan. 1.

He is one of the few longtime U.N. officials who have won the trust of Boutros-Ghali.