Roy Cohn claims that, like Muhammad Ali, he is retiring from the ring. He will no longer handle criminal trials. Except for one, which could turn out to be one hell of a swan song.

The case involves the recent charge by his client, Steve Rubell, owner of New York's trendy disco Studio 54, that White House Chief of Staff Hamilton Jordan snorted cocaine on the premises last year.

It just so happens that Rubell and two other owners of Studio 54 are under federal indictment for tax evasion.

"Classic Cohn," one New York lawyer said recently about the Jordan allegation. "When I read the story in the paper, I knew he was behind it be fore I saw his name. I didn't even have to read the rest of the article."

"He has done nothing to rehabilitate himself from the old McCarthy days," concluded another prominent attorney. "That has always been his technique."

Roy Marcus Cohn will be remembered by most Americans as the malevolent-looking young man with the hooded eyes who whispered nasty questions to Sen. Joseph McCarthy when he was on the rampage in the 1950s.

As chief counsel to McCarthy's Senate Permanent Subcommittee on Investigations, he conducted communist witch hunts with abandon and at one point told the world that he would "get" the Army during the celebrated Army-McCarthy hearings.

He did this at 26, the same age, as columnist Murray Kempton pointed out, that Alexander the Great was pronounced a living god by Egyptian priests.

By then, he already had helped send the Rosenbergs to the electric chair for spying. His image as a heavy was assured. He has done nothing since then to alter it, because, quite simply, he loves it. As far as Roy Cohn is concerned, there is nothing to rehabilitate.

"McCarthy was right," he said Wednesday in his tiny Manhattan office. "Communism is the threat to freedom in the world today."

That is why Cohn is president of the American Jewish League Against Communism, an organization which is listed in the New York telephone book at 39 E. 68th St., the address of Cohn's law firm -- Saxe, Bacon & Bolan.

Roy Cohn coesn't prosecute anyone anymore. These days, he counsels the rich. He's their problem-solver, their expediter, their shield from the crudities of the streets.

He knows the right people and can place the right calls. He knows virtually every political leader in New York City and socializes with an amalgam of celebrities and pals. He has represented the Moony newspaper, Christina Ford (briefly) and Tony Salerno. Roy Cohn has become a man for all seasons.

At 52, he has bankrolled his ferocious image as The Bad Seed of the '50s and criminal defendant in the '60s into a lucrative private practice where he does damned near anything he pleases.

"My scare value is high," he conceded. "My area is controversy. My tough front is my biggest asset. I don't write polite letters."

It is ironic that despite his consistent craving for attention over the years, he opposes the disclosure of the Jordan allegation by his client to federal authorities.At least that's what he says.

"I was against the whole thing from the beginning, but I was on a Greek island (Mykonos) when it happened, and I only found out about it when I got back to New York," he explained. "I would have absolutely left it out. It doesn't do anybody any good."

His conviction sounds genuine, because Cohn has always been keenly aware of events outside the courtroom and their potential to shape the outcome of the trial. Quite simply, he thinks that the revelations are bad tactics and, if nothing else, Cohn has always been a superb gamesman.

His desk phone rings, and he offers Sheldon Tannen, owner of 21, the celebrated New York restaurant, is calling about funeral arrangement for Samuel Newhouse, the 84-year-old newspaper magnate who died that day. Sy Newhouse, his son, Cohn claims as his closest friend in the world. He tells Tannen he'll do anything he can.

"I don't like to plea-bargain," Cohn said when he finished the call. "That's not my style. I like to fight."

Which is another reason he claims to oppose the Jordan allegations. They were produced by Rubell and Studio 54 co-owner Ian Schrager, represented separately by Washington attorney Mitchell Rogovin, in the hope of obtaining a break in their own case. It was Rogovin who, upon entering the case, learned of the cocaine story and, after a good deal of thought, offered it to the authorities as proof of "substantial cooperation."

"Mr. Cohn is entitled to his views," Rogovin said this week. "He's a very able trial lawyer. I hope he's wrong here."

Cohn concedes that there's a "fifty-fifty" chance of a plea-bargain settlement in the case, but for now he says he's preparing for court.

Had the allegations from Rubell and Schrager come 10 days earlier, Cohn still wouldn't have been able to counsel against releasing them, because he was in Monte Carlo then, closing the deal that will turn over 51 percent of 21 to one of his clients -- Baroness Sandra di Portanova, an heir to the Cullen oil fortune.

Cohn is on the road a lot these days, and he doesn't visit places like Philadelphia. Later this month, for example, he flies to Paris to talk about the McCarthy era on French television. Then he's off to London to see the di Portanovas, then to Singapore to see an old friend, and finally to Perth, Australia, to open a museum, of all things.

Cohn handles the unsavory rich as well as the ones in the Social Register. He has represented members of the Gambino and Galante families.

"Every person in the United States is entitled to counsel of their choice. That's a basic canon of our legal system. I don't expect to draw a pedigree of my clients. Besides Gambino was very anti-drugs," he said.

Cohn's anti-drug crusade rivals his battle against communism. "That's one case I won't do -- a hard-drug case," he said. "I know that runs counter to what I just said, but I can't help it I don't think I'd represent anyone who assaulted a policeman or an FBI agent in the line of duty, either."

The tone warms right up to white-collar crime of appalling proportions. He unsuccessfully represented Adela Holzer, "the angel of Broadway," who produced hits like "Hair" before being convicted this spring of bilking investors of almost $13 million.

And he spent the early part of this week in court on a Florida land-fraud case involving millions.

Cohn is on the phone again, talking about more funeral plans for Newhouse. He listens more than he talks. He forgets what's going on around him.

As the star of the firm, Cohn could have any office he wants in the townhouse on 68th Street. But he sits in a tiny room in the basement of the building, cushioned from the heat by air conditioning, protected from the sun by drawn curtains.

His walls are full of his life: a now-famous shot of him whispering to MaCarthy; a portrait of J. Edgar Hoover; another of Cardinal Terence Cooke; another of his father, Albert Cohn, a New York Court of Appeals judge; and one of himself, sent by columnist William Safire. Reggie Jackson, the most expensive toy of Cohn's good friend George Steinbrenner, peers from the wall as well.

Cohn is kept company by his considerable collection of stuffed animals, the kind a pre-adolescent collects. Brown bears, green frogs and black dogs line the base of the walls and spill onto a small sofa.

Cohn has a strange office.

There are other seats to fill in the courtroom game besides those of prosecutor and defense counsel -- the defendants'. And Cohn has sat there too -- three times to be exact, on charges ranging from conspiracy to bribery to fraud. He walked away from all of them with acquittals, but will always harbor a grudge against Robert Morgenthau, the man responsible for his three ordeals.

In one of the trials, Cohn watched his defense counsel literally drop dead as he began his summary to the jury. The scene would have been branded intolerably melodramatic if a Hollywood script writer had tried to do it, but in real life, Cohn then rose to the occasion by presenting his own defense summary for a day and a half and walked away a free man. That performance did wonders for Roy Cohn.

It is rare -- at any time of year -- that Roy Cohn is not tan. He loves the sun, even though a doctor told him a few years ago that he had a premalignant skin condition. But he still thinks it's fortunate that many of his clients frolic in places like Monte Carlo.

Cohn's deep, even tan adds to his incredible face, which has been the subject of a good deal of discussion over the years. Some see it and immediately think of evil. To others, it's just a homely, unsettling face. But it's easy to see why many have found it menacing -- and how Cohn has exploited it.

To look at Cohn is to confront first his bulging, pale blue eyes, which can display all the warmth of a moray eel at times. A deep, undisciplined scar runs down his large nose, past the pockets under his eyes to a mouth that seems to talk without moving. It's hard to see his teeth.

Cohn had a face-lift recently, the scars from which have all but disappeared into his close-cropped gray hair. But he appeared at the Holzer sentencing with a few dozen stitches working their way up the sides of his face, over his ears and out of sight. He looked incredible.

Cohn is tiny -- a bantam of 145 pounds with a large head and a small, spare frame. He takes care of his body, he says, by water-skiing on Long Island Sound near his home in Greenwich, Conn., a 37-minute drive from his office, where he also keeps a room.

"I love to ski," he said. "It gives me a great deal of privacy. There's no telephone at the other end of the line."

He tries to ski early in the morning, before his well-heeled clients get up. Picture Roy Cohn skimming along the flat surface of the Sound, blissfully weaving his way back and forth across the wake of his 16-foot boat on two skis ("I have a lousy sense of balance"), mapping out the strategy of the day.

Every now and then, Cohn will make the drive himself, if for no reason other than to rebut the legion of people who say he's an awful driver. But usually a driver from the firm will squire him out and back in a 1957 Rolls Royce, a caramel Cadillac coupe or a white Cadillac convertible specially adapted for him by his good friend Victor Potampkin, owner of the largest Cadillac dealership in New York City.

The car was turned into a convertible for Cohn by Potampkin after Cadillac stopped making convertibles a few years ago.

Cohn has a strange though very comfortable financial arrangement with his law firm. In exchange for the lion's share of business he brings in, the firm picks up all costs associated with the job, which in his case cover almost everything he does.

"I'm the works here," he said without a trace of modesty. "I'm the big income producer, and 99 percent of my life is spent doing business."

Cohn puts his expenses -- which include part of the rent on his Greenwich house, cars, meals, travel and other incidentals -- at about three-quarters of a million dollars a year. "And I produce double that amount of business," he added.

Cohn does retain the right to keep the legal fees he earns outside of New York and Connecticut, which he says are enough to pay for his clothes and whatever else he wants. (He is a fastidious dresser.) This amount, he says is somewhere over $100,000 a year.

Cohn says his withdrawal from criminal trial work is a step toward a new life for him. He wants to concentrate on "corporate" business like the brokering of the sale of 21. He wants to teach more law, do more writing and reading -- broaden his horizons. One might call it the greening of Roy Cohn.

This decision stems in part from recent statutes concerning speedy trials. He claims he can't prepare adequately under the new laws. "You're not going to see people like Ed Williams or me in the courtroom much anymore," he concluded.

His detractors say he is simply going where he can make more money with less work. They claim he has spread himself too thin for years.

Cohn loves to talk about his seven godchildred ("There are seven little Roys out there"), perhaps because he knows he will never have any children of his own. By all accounts, he will never marry, although he says he has come close three times in his life.

"Barbara Walters and I came close once," he said, "I spent an hour in a phone booth at a restaurant trying to talk her out of marrying Lee Guber. I lost."

It appears he is capable of rare degrees of devotion and cruelty. His loyalty to his friends is an legendary as his instinctive move for the juglar. He is at once charming and crude, street-smart and sophisticated. He might do it over again given the chance.

"I would have watched things more closely," was all he could offer of his performance with McCarthy.

"If you want an example of things I did which I now regret, look at when I was a federal prosecutor," he said. "I pushed for huge conspiracy trials then, and I'm dead against them today.

"But it's the double standard of this whole thing that I can't accept," he added. "What about [the late Sen. John] McClellen and the other committees that operated the same way as McCarthy? You never hear anything about them."

Cohn smiles. He does it rarely, doling out warmth like candy to a child. "I sleep well at night," he concluded. "I won't by saying 'please forgive me' on my deathbed."