NEW YORK TIMES | VANESSA FRIEDMAN

In a sign that the turbulence that has significantly altered the luxury creative landscape in recent years has moved to the executive suites, LVMH Moët Hennessy Louis Vuitton, the world’s largest luxury group, has engaged in the fashion equivalent of a cabinet reshuffle.

Sidney Toledano, the man who built Christian Dior into a multibillion-dollar global powerhouse and shepherded it successfully through one of fashion’s biggest scandals, will be stepping down from the helm of the brand after leading it for almost 20 years. He will become chairman and chief executive of the LVMH Fashion Group, the division that encompasses eight of the group’s smaller brands including Céline, Givenchy, Loewe, and Emilio Pucci. He will also join the LVMH executive committee. Pietro Beccari, the chief executive of Fendi, another brand in the LVMH stable, will become chief executive of Dior.

Pierre-Yves Roussel, the former head of LVMH Fashion Group and the architect of its evolution and expansion, is leaving that role after 10 years to become a special adviser to the LVMH chairman, Bernard Arnault.

The scale of the changes reflects the unrest in the wider industry, which was rebounding this year after a period of difficulty.

The pace of designer hirings and firings has increased to an extraordinary extent over the last two years; just last week Christopher Bailey, president and chief creative officer of Burberry, announced he was leaving the brand. Brexit-induced uncertainty and fears of violence have affected consumer shopping habits, and the scale of digital transformation has altered the retail landscape. The C.E.O. musical chairs point to a conviction that new points of view are necessary to identify the opportunities in the turmoil.

“This is the right moment for change,” Mr. Toledano, 66, said in a telephone interview. He added that when Mr. Arnault broached the subject of his moving to the Fashion Group, “I accepted before he had finished asking.”

“I look around and see people retiring, and that is something I hate,” Mr. Toledano added. “I was never bored at Dior, but it was time for a new direction. I believe in the luxury market — I don’t need to see analysis from consulting firms — and think we can catch more market share.”

Dior holds a special significance in both the group and the overall sector as the first luxury brand acquired by Mr. Arnault in 1985, and is the cornerstone of his empire.

Along with Mr. Arnault, Mr. Toledano, who joined Dior in 1994 as director of leather goods and was named chief executive in 1998, was the mastermind behind the transformation of the elite French fashion house into a worldwide phenomenon that became something of a strategic model for other luxury brands on how to bridge haute couture and haute pop culture.

During his tenure, Mr. Toledano oversaw the opening of almost 200 international stores, the growth of celebrity partnerships, the rise of the star designer, and the evolution of the fashion show into a major marketing initiative. His nearly two-decade stint was in contrast with those of most luxury-sector chief executives, who tended to change jobs more often than even their designers did.

Widely respected, Mr. Toledano wielded influence that has reached far beyond LVMH, through the ascension of a group of chief executives who once worked for him at Dior, including Michael Burke, the chief executive of Louis Vuitton; Claus-Dietrich Lahrs, the head of Bottega Veneta; Valérie Hermann, the president of global brands at Ralph Lauren, and Pierre Denis, the chief executive of Jimmy Choo.

Mr. Toledano also steered the Paris-based Dior through the transition to a new creative director after the firing of John Galliano. Mr. Galliano’s flamboyance and dramatic vision had helped to propel Dior out of fustiness and into relevance, but he was forced out in 2011 after a drug- and alcohol-fueled anti-Semitic outburst. He was replaced by Raf Simons, but Mr. Simons stayed only three years and was succeeded by Maria Grazia Chiuri, the brand’s first female designer.

The executive change comes at a crucial point for Dior: LVMH announced the purchase of Dior, which had previously been a sister brand under a shared holding company last April, and after a comprehensive retrospectiveof the fashion house opened at the Musée des Arts Décoratifs in Paris this past summer to mark its 70th birthday. The Dior merger, in particular, created a giant fashion and leather goods group with combined annual sales of more than 5 billion euros, or $5.8 billion, according to the Exane BNP Paribas analyst Luca Solca.

LVMH has consistently posted strong sales in what has proved to be a volatile global luxury goods market in recent years. Last month it reported higher-than-expected revenue growth for the third quarter, with like-for-like revenues, which strip out currency swings and acquisitions or disposals, growing 12 percent from a year earlier to €30.1 billion.

With Mr. Beccari, who helped build Fendi into the third-largest brand in the LVMH fashion and leather goods division, after Louis Vuitton and Dior, LVMH will be keeping its leadership in the family, while ensuring that smaller brands, many of which have been in flux, are given renewed attention.

Mr. Beccari’s appointment “signals a new era,” Mr. Arnault said in a statement.

“Sidney Toledano is the driving force behind the huge success of Christian Dior Couture around the world,” Mr. Arnault said. “I want to offer my profound gratitude and am delighted that we will continue to work together and benefit from his expertise.”

Mr. Toledano will have his hands full in his new role. Though sales at the fashion group have tripled over the last decade under Mr. Roussel, with most brands becoming profitable for the first time, currentlyEmilio Pucci is searching for a designer; there are questions about whether Phoebe Philo, the feted creative director of Céline, will stay for much longer; and Marc Jacobs, which in 2013 was thought to be a possible candidate for an initial public offering, has struggled with a brand reorganization and management change.

Robert Burke, founder of an eponymous luxury consultancy, said: “This is a sign LVMH is getting serious about growing their smaller brands. A few of them, such as Céline and Givenchy, have the potential to be big global companies, and there is no one better suited to get them there than Sidney. He understands both the silhouette of a handbag and global strategy.”

“What I have learned from 20 years at Dior is you have to be pragmatic, concrete, listen to people a lot, and give guidance,” Mr. Toledano said of how he will approach his new role. “People want leadership.”

Mr. Beccari and Mr. Toledano are to assume their new posts next year. A replacement for Mr. Beccari has not been announced.