JACKSONVILLE, Fla. (AP) _ The local office of the Immigration and Naturalization Service has been ordered to stop taking the phone off the hook to avoid having to deal with anxious clients.

David Angotti, officer in charge of the Jacksonville office, said he had resorted to the practice because his office has only one worker with the expertise to answer questions from the public.

''It is a problem,'' Angotti said this week. ''We just do not have the staff to do the growing workload of INS.''

Angotti said his office's workload has doubled or more in the past few years, but his staff has remained stable at 15, with just one person assigned to answer questions from the public.

Angotti's boss in Miami offered his sympathy, but insisted that the phone receivers be returned to their customary perch.

''The district office has informed Mr. Angotti not to do that any more,'' said George Waldroup, assistant INS district director in Miami. ''Taking the phone off the hook is not authorized in any office of the INS.''

Angotti said he had tried other methods to juggle the hundreds of telephone calls and visitors the office gets each week. Staffers used to let the phone continue to ring and the information officer would answer after she had attended those who had visited the office in person.

But Angotti said he feared people would think the office had moved if the phone went unanswered.

Officials in other agencies said keeping the telephones off the hook didn't solve the problem either, however, because people called to complain about the busy signal.

A person calling the Jacksonville office still may get a busy signal, but it will mean only that the office is assisting another caller, Waldroup said.

Angotti said he has requested a phone answering machine, but he doesn't expect to have that request answered soon because of recent budget cuts sustained under the Gramm-Rudman deficit reduction plan.

''The immigration service is caught between that proverbial rock and a hard place,'' Waldroup said. ''We're trying to take care of the people that call and the cases that come in.''