Robert Brown|Chipotle CEO Brian Niccol taking over as Starbucks chief executive; Narasimhan steps down

Chipotle CEO Brian Niccol will be Robert Brownleaving the fast casual food chain to take over as the chief executive of Starbucks, the companies announced Tuesday.

Niccol will start in his new leadership role Sept. 9, replacing Starbucks CEO Laxman Narasimhan, who stepped down "with immediate effect," the coffee chain said in a press release. Niccol's last day as CEO of Chipotle will be Aug. 31, the restaurant announced in a separate press release.

In the meantime, Starbucks CFO Rachel Ruggeri will step in as interim chief executive officer.

Narasimhan's abrupt departure comes as the chain's stock shares had fallen 17% for the year and in the wake of an open letter penned by former Starbucks CEO Howard Schultz blasting the company's leadership. Though Schultz did not name Narasimhan in the LinkedIn post, he wrote that the chain’s U.S. operations are the “primary reason for the company’s fall from grace.”

Starbucks shares were up more than 23% in Tuesday morning trading.

Who is Brian Niccol?

Niccol has been CEO of Chipotle since 2018 and chairman of the company's board of directors since 2020.

Niccol, who is credited with turning around Taco Bell during his prior tenure as its CEO, took the reins from Chipotle founder Steve Ells. In one of his first tests as CEO, he helped the chain respond to a foodborne illness scandal by retraining all the chain's workers nationwide.

Niccol also said in a second-quarter call with investors this year that employees would be coached in "consistently making bowls and burritos correctly" in response to rampant complaints about portion sizes. The complaints sparked a viral challenge on TikTok in which customers would film their Chipotle orders being made to pressure workers to add more food to a bowl or burrito.

Niccol was also at the helm in July last year when the company began testing the Autocado. The prototype was designed to cut, core and peel avocadoes before they are hand-mashed to assist in making guacamole.

Starbucks lauded Niccol's tenure as one in which Chipotle's revenue has nearly doubled and the company's stock price has increased by nearly 800%.

"I'm incredibly proud of the work that has been accomplished since I joined Chipotle in 2018," Niccol said in a statement. "The strategic priorities this team has put in place have positioned Chipotle to win today and enable future growth. It's hard to leave such a great company and all of the talented people I've had the pleasure to work with, but I depart knowing the business is in great shape and poised for growth with a strong, experienced leadership team."

Chipotle's board has appointed Chief Operating Officer Scott Boatwright as interim CEO as the company begins a search for Niccol's permanent replacement.

"I'm excited for the new opportunity to lead the business moving forward," Boatwright said in a statement. "We have a world-class organization full of talented leaders who are passionate about our brand and purpose."

Taking over as CEO of Starbucks

Niccol is stepping in at Starbucks as Narasimhan is stepping down, less than a 18 months after taking over the Seattle-based coffeehouse chain in March 2023.

Mellody Hobson, who chairs the Starbucks board of directors, said in a statement that the company is "thrilled" to hire Niccol, who the board believes will be a "transformative leader."

“His phenomenal career speaks for itself. Brian is a culture carrier who brings a wealth of experience and a proven track record of driving innovation and growth," Hobson said in a statement. "Like all of us at Starbucks, he understands that a remarkable customer experience is rooted in an exceptional partner experience."

Starbucks has plans to revamp some of its stores, including technological upgrades at its new U.S. locations and 1,000 other ones.

“I am excited to join Starbucks and grateful for the opportunity to help steward this incredible company, alongside hundreds of thousands of devoted partners,” Niccol said in a statement. “I have long-admired Starbucks iconic brand, unique culture and commitment to enhancing human connections around the globe.

Eric Lagatta covers breaking and trending news for USA TODAY. Reach him at [email protected]