John W. Marriott III said yesterday that he is leaving the company that his family built from a Washington, D.C., root beer stand into a global food and hotel empire, the apparent start of a transition away from day-to-day family control of one of the region's most prominent corporations.

As the middle son of Marriott International's chairman and chief executive J.W. "Bill" Marriott Jr., he had been a leading candidate to take over the firm when his father, 73, retires. But word that he will leave the Bethesda company in January seemed to confirm what many Marriott-watchers have long suspected: Executive control of the world's largest hotel chain will pass from the family that built the company.

"This clearly indicates that someone other than a family member will likely be the next chief executive," said William C. Marks, an analyst with JMP Securities. The focus now, he said, is on two longtime executives: Arne M. Sorenson, the chief financial officer, and William J. Shaw, the president.

Marriott's deep roots in the region's business community date back to when Washington was mostly a one-company town -- a government town. Though that has largely changed through the years, with dozens of high-tech startups and government contractors producing a bevy of millionaires, Marriott's presence has been a constant, with the family playing major roles in the civic and philanthropic worlds.

Bill Marriott has been a member of the Federal City Council, an influential civic organization focused on development in the District, for decades. The company has supported local causes such as the Marriott Hospitality Public Charter High School, a District public school that prepares high school students for careers in the hotel business. Sorenson also has ties to Washington; before joining Marriott, he was a Washington-based partner with law firm Latham & Watkins.

John W. Marriott III, 44, joined the family business in 1976, four years after his father took over as chief executive. As executive vice president of lodging, he had been credited recently with reviving the firm's 14 different brands -- from the moderately priced Fairfield Inn to the extravagant Ritz-Carlton.

While the announcement appears to take John Marriott out of the running to control the company, he was promoted to vice chairman of the board of directors, suggesting the family would continue to wield influence in the firm's operations. The family controls 23 percent of company stock.

John Marriott outranked his brothers Stephen and David on the corporate ladder in the company their grandparents founded in 1927 on 14th Street NW. The root beer stand led to the Hot Shoppes restaurant chain, followed by Roy Rogers and Big Boy. The family opened their first hotel in Arlington in 1957.

Today the company has 133,000 employees -- 13,165 locally -- and more than $10 billion a year in revenue. With that kind of money at stake, particularly in a family-run business, questions of succession become complicated. The media conglomerate Murdoch family is wrestling with similar issues, with Rupert Murdoch's oldest son Lachlan recently leaving the family business.

Though Bill Marriott and the company strongly maintain that he has no plans to step aside anytime soon, that hasn't stopped speculation both inside and outside of the firm about who will one day take over. The focus, in part, had naturally been on a family member, which is not surprising to anyone familiar with Bill Marriott's persona as a folksy, devout Mormon, a tough businessman who also cares deeply about family life and values.

Though John Marriott is known to be more introverted than his father, he is clearly trusted with the family's fortune. He founded JWM Family Enterprises, a private investment partnership with more than $600 million in assets. He will become the organization's chief executive.

John Marriott's position as a possible successor to his father was largely a function of family circumstances. His brother David, senior vice president of global and field sales, is only 32 years old and not fully groomed as a top executive. His older brother Stephen, a senior vice president of culture and special events, has a hearing and vision impairment that developed when he was a teenager and has progressed.

Their sister Debbie does not work in the business, though her husband, Ron Harrison, is in charge of Canadian operations.

John Marriott and his father were not available for comment yesterday, company officials said. However, Charlotte Sterling, executive vice president of communications, said that the company's board has "always felt very strongly that the right person should lead the company, whether it's a Marriott or not."

Staff writer Neil Irwin contributed to this report.

John W. Marriott III

J.W. Marriott Jr., right, and sons, left to right, John, Stephen and David pulled a ceremonial gold rope to unveil a model of the hotel chain's new room design, in New York's Times Square on Sept. 21.