LONDON — Victor Lownes, a former executive of Playboy who helped forge the brand’s hedonistic ethos and put much of the swing into the “Swinging London” era, has died at 88.

Friend Barbara Haigh, a former “bunny girl” at London’s Playboy Club, said Lownes died in his sleep Wednesday at a London hospital after suffering a heart attack at a New Year’s party.

Haigh called Lownes “a total gentleman,” adding he was “the best boss anyone could ever have wished for.”

Born in Buffalo, New York, in 1928, Lownes met Hugh Hefner at a Chicago party in the 1950s and recognized a kindred spirit. Lownes went to work for Hefner’s new Playboy magazine, whose blend of sophistication and titillation was a recipe for riches in the increasingly permissive — but firmly male-dominated — times.

The first Playboy Club opened in Chicago in 1960, offering live music and comedy, alongside cocktails served by hostesses in bustiers and bunny ears — a costume based on Playboy’s tuxedo-wearing bunny logo.

In the 1960s, Lownes traveled to Britain to open Europe’s first Playboy Club, complete with a casino, in London’s Park Lane. Its opening night in 1966 drew an elite crowd that included Julie Christie, Woody Allen and Rudolf Nureyev; Beatles and aristocrats were soon among its clientele.

Lownes became a pillar of London nightlife, holding epic parties at his home in the city and later at Stocks House, an 18th-century country mansion where he installed Britain’s largest hot tub and set up a training camp for Playboy bunnies.

An unapologetic hedonist, he is credited with an entry in the Oxford Dictionary of Humorous Quotations: “What is a promiscuous person? It’s usually someone who is getting more sex than you are.”

Lownes helped lead Playboy’s expansion into gambling and headed its casino division. For a time he was reputed to be Britain’s highest-paid executive. But when British gambling authorities began investigating alleged licensing irregularities in the early 1980s, Hefner fired him. Playboy’s U.K. gambling licenses were revoked, and within a decade all the more than 20 original Playboy Clubs around the world had closed.

Lownes also invested time and money in theater and film productions, financing “And Now for Something Completely Different,” the first film featuring the Monty Python comedy troupe. He also persuaded Hefner to fund Roman Polanski’s bloody 1971 movie version of “Macbeth.”

Lownes left his first wife and two young children in the 1950s to embark on a life as a “Playboy Extraordinary” — the title of his autobiography.

In 1984, he married Marilyn Cole, a British Playboy bunny and model — the 1973 “Playmate of the Year” — who went on to a career in journalism. She survives him, as do two children from his first marriage.

Haigh said his funeral will be held Jan. 26 at St. Luke’s Church in London’s Chelsea district.

“We are expecting a large turnout for a truly lovely, wonderful man, who loved a good time but was nothing like the way he has been maligned,” she said.