NEW YORK -- Disney CEO Bob Iger, who steered the company's absorption of Star Wars, Pixar, Marvel and Fox's entertainment businesses and the launch of a Netflix challenger, is stepping down immediately, the company said in a surprise announcement Tuesday.

The Walt Disney Co. named as his replacement Bob Chapek, most recently chairman of Disney's parks, experiences and products business.

"Did not see this coming -- Wowza," tweeted LightShed media analyst Rich Greenfield.

Iger will remain executive chairman through the end of his contract on Dec. 31, 2021. Besides leading the board, Iger said he will spend more time on Disney's creative endeavors, including the ESPN sports network, the newly acquired Fox studios and the Hulu and Disney Plus streaming services. He said he could not do that while running Disney on a day-to-day basis.

“It was not accelerated for any particular reason other than I felt the need was now to make this change," Iger said on a conference call with reporters and analysts.

Iger steered Disney through the successful purchases of Lucasfilms, Marvel, Pixar and other brands that became big moneymakers for Disney. Last year, the top five movies in U.S. and Canada theaters were all Disney movies, including two from Marvel and one from Pixar. With the Dec. 20 release of the latest “Star Wars" movie, Disney had seven movies that each sold at least $1 billion in tickets worldwide last year.

Iger's most recent coup was orchestrating a $71 billion purchase of Fox's entertainment business in March and launching the Disney Plus streaming service in November. That service got nearly 29 million paid subscribers in less than three months. In a statement, Iger said it was the “optimal time" for a transition.

Pivotal Research Group analyst Jeffrey Wlodarczak said Iger had implied he would stay until his contract ended in 2021.

"On the other hand, they just successfully closed the Fox deal and had an unquestionably successful launch of Disney Plus so maybe he felt earlier was better to hand off the reins," he said.

Colin Gillis, director of research at Chatham Road Partners, said the choice of Chapek seems solid because his parks division has had success.

Chapek said that while he has not led television networks or streaming services, his background in consumer-oriented businesses should help. Chapek and Iger both stressed that Disney would continue on the direction it had already been taking.

Disney is facing challenges to its traditional media business as cord-cutting picks up, meaning less fees from cable and satellite companies to carry Disney networks such as ABC, ESPN and Freeform. Disney's own streaming services require the company to forgo money in licensing revenue, although the company is betting that money from subscriptions will eventually make up for that.

In the short term, Disney parks in Hong Kong and Shanghai, China, remain closed because of the coronavirus outbreak. In a CNBC interview, Chapek said the outbreak may be a "bump in the road," but he said the company could weather it given “affinity for the brand."

Iger told CNBC he had no plans to stay with Disney beyond next year.

Iger's appointment as CEO in 2005 had been accompanied by controversy and protest from dissident shareholders Roy E. Disney and Stanley Gold. But he has come to be seen as a golden-boy top executive, and even someone who could run for president.

Iger told Vogue in 2018 that he had started seriously exploring a run for president because he is "horrified at the state of politics in America today," but the Fox deal stopped his plans. Oprah Winfrey told Vogue that she “really, really pushed him to run.”

Iger, a former weatherman, joined ABC in 1974, 22 years before Disney bought the network.

At ABC, Iger developed such successful programs as “Home Improvement,” “The Drew Carey Show,” and “America’s Funniest Home Videos” and was instrumental in launching the quiz show “Who Wants to Be a Millionaire.” He was also criticized for cancelling well-regarded but expensive shows such as “Twin Peaks” and “thirtysomething.”

Since Iger became CEO, Disney's stock price has risen fivefold. Its stock fell more than 2% in extended trading following the announcement, on top of a broader market selloff on virus fears during regular trading.

Iger, 69, was the second-highest paid CEO in 2018, as calculated by The Associated Press and Equilar, an executive data firm. He earned $65.6 million. The top earner was Discovery's David Zaslav who earned $129.5 million.

Susan Arnold, the independent lead director of the Disney board, said succession planning had been ongoing for several years.

Chapek, 60, is only the seventh CEO in Disney history. Chapek was head of the parks, experiences and products division since it was created in 2018. He was previously head of parks and resorts and before that president of consumer products.