Daniel N. Perlmutter, one of New York's most aggressive young prosecutors before he began stealing to support his taste for cocaine and high-class prostitutes, was sentenced in New York yesterday to three years in prison.

The sentence completed the collapse of a once-promising career that began with an affluent childhood in South Orange, N.J., and ended in New York hotel rooms where Perlmutter shared stolen drugs with $125-an-hour call girls, according to documents filed by federal prosecutors. They said he eventually stole from defendants and fellow prosecutors.

Perlmutter, 29, pled guilty in October to stealing cocaine and heroin worth $450,000 from a safe in the U.S. attorney's office in Manhattan, where he was rapidly becoming one of the city's top federal narcotics prosecutors.

A Phi Beta Kappa graduate of Williams College and a former editor of the New York University Law Review, Perlmutter fought back tears as he asked U.S. District Court Judge Charles Stewart not to send him to prison.

"Nothing in my life came easy to me -- I worked hard to get the things I achieved," Perlmutter said. "I don't know why I did what I did."

Perlmutter said he became a cocaine addict last year. "With the failure of my second marriage, I seemed to fail with it," he said. "By some horrible twist of fate, at the lowest point of my life I was introduced to cocaine."

Summing up, he said: "I don't have anybody in this world. I'm adopted; there are no blood relatives. I am an outcast to all those people who knew and loved me."

But Stewart told Perlmutter he had "violated and abused the trust placed in you." The judge also gave him five years' probation and ordered him to repay the $41,800 in cash he stole from the safe where evidence was stored.

The case, part of a recent spate of corruption charges involving federal prosecutors and FBI agents, has been widely viewed as a test of the government's ability to investigate and punish its own. Perlmutter's boss, U.S. Attorney Rudolph W. Giuliani, has likened the case to "a death in the family."

A sentencing memorandum filed by William C. Hendricks III, deputy chief of the Justice Department's Public Integrity Section, described Perlmutter's crimes as carefully planned. According to the memo:

While still married in the summer of 1984, Perlmutter began hiring prostitutes for $50 to $70 a session. He regularly met one of them at the apartment of a fellow assistant U.S. attorney, saying he needed the apartment to debrief drug informers.

Perlmutter accepted a small amount of cocaine from the prostitute, who knew him as an investment banker named Steven. Later, at the New York hotel frequented by another prostitute, he began to buy cocaine for $125 a gram from a night desk clerk who supplied it to prostitutes and their clients.

Prosecutors said Perlmutter first stole $70 from the office safe, using it to hire a prostitute. He then stole $12,000 that was posted as a cash bond by a defendant in one of his cases.

In December 1984, Perlmutter stole 1,000 grams of heroin, the first of a series of drug thefts from the third-floor safe. He took the drugs to his New Jersey home and hid them from his wife, a federal prosecutor in Newark. They separated the following month.

During post-midnight visits to the safe, Perlmutter tried to minimize the chance of detection by stealing drug exhibits already presented in court, prosecutors said. He used the money to frequent such services as Fantasy Escort, which allegedly supplied call girls for $125 an hour and cocaine for $125 a gram.

Although Perlmutter was increasingly absent from the office, he continued to work on the case of a major cocaine trafficker. He later stole part of the evidence -- 845 grams of cocaine -- which he used with his new girlfriend.

Last March, the sentencing memo said, Perlmutter stole the American Express card of a fellow prosecutor and used it to buy gifts for prostitutes. He also stole a blank check from another prosecutor and $50 from the wallet of a New York detective.

In May, after the safe lock was changed, Perlmutter got the combination from another prosecutor's desk, stole some heroin and snorted it. He was arrested six days later and lost his job.