JPMorgan Chase is reshuffling its leadership team, a move that many consider a succession plan even though its longtime chief executive, Jamie Dimon, has signaled he is staying put.

Mr. Dimon, 67, has been head of what is now the largest bank in the United States for nearly two decades, and repeatedly brushed off suggestions that he might step aside. The specter of his eventual departure, however, hangs over JPMorgan as outsiders question whether he might run for public office or serve in a presidential administration.

In a memo to employees Thursday, JPMorgan muddied the matter further. Daniel Pinto, the bank’s chief operating officer and Mr. Dimon’s deputy, is surrendering his title as head of the corporate and investment bank. Mr. Dimon said that he and Mr. Pinto would “continue to jointly manage the company.”

Mr. Pinto’s former responsibilities will be split by Jennifer Piepszak and Troy Rohrbaugh, who will serve as co-chief executives of an expanded commercial and investment bank that brings several lines of the company into one unit. Other banks, including Citigroup and Goldman Sachs, have also simplified their operations in an effort to focus on their highest-earning units, particularly after last spring’s regional banking crisis hammered lenders that expanded too quickly.

JPMorgan is an enviable position compared to its peers. Its shares are up 23 percent over the past year, while the average bank stock has fallen. The bank continues to vacuum up customer deposits, and swooped in to acquire ailing First Republic shortly after Mr. Dimon coordinated a government-backed rescue of the teetering lender.

That stability has not just kept Mr. Dimon in his role for longer than his rivals — he’s the only chief executive of a major bank from the 2008 financial crisis still in his post — but has also helped quell potential disquiet among those hoping to succeed him.

“It’s not a bad gig working for Jamie Dimon. You get paid a lot and you’re one rung away from the most powerful people in the world,” said Michael Mayo, an analyst at Wells Fargo.

Mr. Mayo said he viewed it as a “two-woman race” to become JPMorgan’s next chief executive between Ms. Piepszak and Marianne Lake, who had been jointly running the bank’s consumer business, which includes its retail bank branches and enormous credit card arm. Ms. Piepszak’s promotion this week will give her new exposure to other areas of the business, while Ms. Lake, now sole head of the consumer operations, will stand alone atop that closely watched part of the bank.

Wall Street analysts have long considered Ms. Lake a potential successor to Mr. Dimon.

This week’s reshuffle will also result in the departure of some executives. Others at the bank will see their roles redefined or be promoted to new ones.

Mary Erdoes, who runs JPMorgan’s wealth management business and is perhaps the bank’s most public face after Mr. Dimon, will remain in her current role.

Mr. Dimon has a financial incentive to stay in his post a good deal longer. In addition to his annual pay ($36 million in 2023), he is slated to receive an additional bonus if he’s still chief executive in 2026.