Perry Ellis, whose easy, modern clothes for men and women have influenced American fashion for almost a decade, died yesterday in New York Hospital of viral encephalitis after several days in a coma. He was 46.

His clothes, based on familiar, casual sportswear, were fresh in their quirky way, and they were vastly popular. For many young women today, Perry Ellis was their first designer label. His handknit sweaters with unexpected cable stitches across the shoulders or a single cable down the front, his cropped full pants, and his broad-shouldered jackets with dimpled sleeves were among the huge hits in his multimillion-dollar business. And they were quickly copied by many others.

"He introduced a relaxed, casual attitude that heretofore did not exist and changed a whole generation's way of dressing," said Bloomingdale's fashion director Kal Ruttenstein.

His menswear, which he started in 1980, offered a fresh proportion with new ideas in color and textile mixes that continue to influence the way young men dress. For men he also played with classic shapes, taking the seriousness out of some of those styles.

For his designs Mr. Ellis received every top award many times over, including the Coty Award (selected by the press), the Council of Fashion Designers of America award (voted on by his peers), and the Neiman-Marcus Award. In 1981 he was chosen to represent the United States in Tokyo at a showing of the best designers in the world called The Best of Five.

"I always admire someone who does their own thing. Perry had a wit and a charm that was expressed in his clothes and in his personality," said Ralph Lauren, an Ellis fan from the start.

As for himself, Mr. Ellis, who generally dressed in a blue oxford shirt and khakis, felt that "fashion dies when it is taken too seriously."

"There's more to life than buying a bag or a new dress," he once told an interviewer. "I really try to put clothes in proper perspective. I mean, I design clothes, produce them and sell them, but I'm very aware that you can't take them home to bed with you and make love to them. All those people who have put their careers before love and health and friends must suffer from an emptiness that I just can't imagine. Clothes come pretty far down on my list of priorities."

A native of Portsmouth, Va., Mr. Ellis graduated from the College of William & Mary, joined the Coast Guard, and then earned a graduate degree in business at New York University. His first job was as a buyer at the Miller & Rhoads department store in Richmond.

He was such a master at selling superclassic John Meyer and Villager clothes -- his department sold more than any other in the country -- that he was hired to design the classic shirts, A-line skirts and Shetland sweaters for John Meyer of Norwich. This brought him to New York and its environs.

Mr. Ellis worked for John Meyer for six years through the fashion upheaval of the late 1960s. Partly because of the freedom of those years his work could remain traditional -- "every one has been made all right, whatever your approach is," he once said -- and even after he left in 1974 to work for Vera Neumann, of Vera home accessories and clothes, his designs were anchored in a conservative, familiar style.

By the time Manhattan Industries, the parent company of Vera, gave Mr. Ellis his own line called Portfolio, his spirited touch was apparent. In 1978 he started to design under his own name label.

"I don't like clothes that are new and dominate the woman," Mr. Ellis said when he started his Portfolio line. "My clothes are friendly -- like people you've known for a long time, but who continue to surprise you. Clothes must do the same."

The extraordinary success of his collections led to selected licensees including furs, shoes, scarves and fragrance to name a few. In 1980 he opened a menswear line and in 1984 he added a sportswear collection for Levi Strauss called Perry Ellis America. The total Perry Ellis business volume is expected to pass $260 million at wholesale this year.

According to Laurance C. Leeds, chairman of Manhattan Industries, the Ellis design company will continue. "Perry's strength lay not only in the individual talent but in the way he counseled and trained a wonderful group of young designers by his side," Leeds said.

Mr. Ellis, a bachelor, had been in ill health that forced him to work at home for more than six months. When a friend asked about his health recently, he said, "I've been very down for months because of the death of my special friend Laughlin [Barker] and yet very happy because of the birth of my daughter [Tyler Alexandra Gallagher]. That's what keeps me going."

When asked about the rumors that he had acquired immune deficiency syndrome, he said, "There will always be rumors. They come and go and there is nothing you can do about it. But I know how I feel."

Mr. Ellis made a brief appearance on the runway after his successful collection was presented in New York last month. He was supported by two assistants and faltered as he attempted to take a step. He was admitted to the hospital shortly afterward.

For the past year he had been president of the Council of Fashion Designers. "He helped reshape a lot of things in our business. Designers have a lot of things to thank him for besides his contribution to design," said Calvin Klein. The day before he died Mr. Ellis was reelected president of the group.