Victor Lownes, a longtime Playboy executive who was instrumental in launching a worldwide network of clubs and casinos and who took credit for designing the bunny-tail costumes worn by the clubs’ waitresses, died Jan. 11 at a London hospital. He was 88.

He had a heart attack at a New Year’s party, his wife, Marilyn Cole Lownes, a former Playboy Playmate of the Year, told the Chicago Tribune.

Lownes met Playboy founder Hugh Hefner in 1954, when the magazine was in its infancy. Revolutionary in its boldness, Playboy featured female nudity alongside sophisticated articles and high production values.

Within a year, Lownes became Playboy’s marketing director, helping to guide its advertising toward an upscale, urbane image. He devised one of the magazine’s most effective promotional pitches: “What Sort of Man Reads Playboy?”

Designed to appeal to potential advertisers and to flatter the magazine’s readers, the long-running campaign invariably featured a well-dressed young man on the go, with an attractive woman or two gazing at him in admiration.

The ads described the typical Playboy reader as “a young man destined to go far,” “an avid sportsman, equally at ease in blue waters, on putting greens or snow-white slopes,” or as “a man with a love of life and a lot of living to do.”

In the view of many, Lownes was the embodiment of the Playboy beau ideal, even more than Hefner himself. He was knowledgeable about art, music and the theater and had graduated from the University of Chicago at 19. He had an air of sophistication and seemed irresistible to women.

“At about 17,” a college roommate recalled to the Chicago Maroon student newspaper in 2012, “we thought he was a man of the world. …We’d look down on the street and we’d see this convertible car … and Victor would get out and there would be girls running about kissing and saying ‘Goodbye!’ and hugging.”

Lownes married for the first time at 18, but within a few years was divorced and ready to explore what became known as the Playboy lifestyle.

In 1959, Playboy published a feature about a Chicago club with provocatively dressed waitresses. The magazine received thousands of letters from the sort of men who read Playboy, asking how they could join.

“I thought we ought to start a club ourselves, so we started it in 1960,” Lownes told The Washington Post in 1977. He also said he came up with the idea to dress the club’s waitresses, or bunnies, in revealing outfits that included bunny ears, a fluffy tail and a bow tie.

“Hefner was against the bunny idea at first,” Mr. Lownes told The Post. “He wanted girls in shortie nightgowns.”

Lownes’ vision prevailed, and a string of Playboy clubs began to pop up across the country. He moved to London, where he launched the first overseas outpost in 1966.

With the added attraction of a casino, the London Playboy Club flourished. Lownes opened other Playboy-owned casinos in England, plus clubs and hotels around the world. His division of the company produced twice as much cash for the bottom line as Playboy magazine, which once had as many as 7 million subscribers.

“Privately, publicly and commercially,” Lownes said, “I think sex is good.”

He became known as the highest-paid business executive in Britain and held more Playboy stock than anyone outside the Hefner family. He had a chauffeur-driven Rolls-Royce, took up fox hunting and owned a pet monkey.

He threw lavish, celebrity-studded parties at his London home and country estate. After one particularly rousing New Year’s Eve party, a neighbor complained, “The swimming pool was alive to the cries of naked ladies. And they were not singing ‘Auld Lang Syne.’ “

Lownes was Playboy personified. He supervised the training of the women who became bunnies – one odd job requirement was that they had to memorize the multiplication table through 17 – and often ended up dating them.

“I tried to avoid saying, ‘I love you,’ ” he said. “I didn’t want anybody to have any illusions.”

In 1981, British authorities began to investigate irregularities at the London Playboy Club, such as illegal credit extended to gamblers. Lownes brushed off the charges as technicalities, but he was soon fired by Hefner, and Playboy’s British gambling licenses were revoked. The Playboy clubs and casinos closed, and Lownes and Hefner did not speak for years.

Victor Aubrey Lownes III was born April 17, 1928, in Buffalo. His family owned a company that made locks for bank vaults.

As an adolescent, Lownes was on a hunting trip in the Florida Everglades when he accidentally shot and killed a friend. He was sent to a military school in New Mexico, then entered the University of Chicago at 16. He graduated in 1947.

His marriage to a fellow student, Judith Downs, ended in divorce.

After college, Lownes joined a Chicago branch of the family business.

“I was promoted to manager within a few months,” he reportedly said, “due solely to hard work, conscientiousness and the fact that my grandfather owned the company.”

He soon grew bored and began to promote entertainers before joining Playboy.

In 1982, Lownes published an autobiography, “Playboy Extraordinary.” Two years later, he married his longtime girlfriend, Marilyn Cole, who was Playboy’s Playmate of the Year in 1973. (“I did the first full frontal,” she explained to The Post in 1977.)

In addition to his wife, survivors include two children from his first marriage; two grandchildren; and two great-grandchildren.

Lownes helped found the Playboy Jazz Festival and over the years invested in various dramatic and film productions, including the play “Other People’s Money,” by Jerry Sterner, the 1971 Monty Python film, “And Now for Something Completely Different,” and the 1990s theatrical spectacle “Stomp.”

Lownes accumulated one of the world’s largest collections of erotic art and is often cited for coining a phrase that has entered common parlance: “A promiscuous person is someone who is getting more sex than you are.”