NEW YORK (AP) _ A state judge on Tuesday ordered an insurance company to pay for a bone marrow transplant that doctors said may save the life of a man with an AIDS- related illness.

Supreme Court Justice Elliott Wilk rejected the contention by Empire Blue Cross and Blue Shield that the operation, used for years to treat people with impaired immune systems, was experimental when used to treat AIDS.

Wilk issued a preliminary order directing Empire Blue Cross and Blue Shield to pay the estimated $150,000 cost of the operation for Thomas Bradley.

His physician, Dr. H. Kent Holland of Johns Hopkins Oncology Center in Baltimore, said in a sworn statement that Bradley's condition was deteriorating and that the New York man could soon become too weak to survive the transplant.

''Time is therefore of the essence,'' Holland said.

Bradley, 46, was about to undergo the operation earlier this month when the insurance company notified him it would not cover experimental procedures.

Wilk's decision sends a message that a treatment ''doesn't become experimental all over again just because it's being used to treat AIDS,'' said Bradley's lawyer, Evan Wolfson.

The insurance company said in a statement that it would consider appealing the ruling.

''Despite our real sympathy for Mr. Bradley, we have an obligation to safeguard the resources entrusted to us by millions of subscribers to cover medical care that's been proven beneficial and appropriate,'' said spokesman John Kelly.

Bradley, an administrator in the Suffolk County school district of Bayport- Blue Point, wanted to have bone marrow transplant as soon as possible, said Wolfson.

Bradley had a 90 percent chance of surviving the operation, which could extend his life by at least two years, Holland said in his statement.

His donor is his identical twin, Bob, a teacher in the same district. Doctors said the fact that the two are identical twins should greatly enhance the chances for success.

Bradley learned he was infected with HIV, the virus that causes AIDS, in 1986 and has a severely depressed immune system. He was diagnosed with AIDS- related condition, or ARC, because he has suffered the specific opportunistic infections listed by the Centers for Disease Control as defining AIDS, Wolfson said.

Johns Hopkins spokeswoman Valerie Mehl said six people with AIDS have undergone bone marrow transplants at the Baltimore center in the past 18 months. Two have since died of causes unrelated to the operation, she said.