CEO of leading US bank JPMorgan Chase, Jamie Dimon, was recovering after emergency heart surgery Thursday, once again bringing the question of the financial institution's succession plans to the fore.

Dimon's operation was to repair an "acute aortic dissection," according to an internal letter sent to employees and seen by AFP. 

"The good news is that it was caught early and the surgery was successful," the letter said. "He is awake, alert and recovering well."

The company did not indicate how long Dimon might be out of commission in recovery.

Head of the company's investment bank Daniel Pinto and head of the consumer bank Gordon Smith will take over Dimon's day-to-day duties.

Both are among the contenders under consideration to succeed Dimon, 63 -- a matter which could now take on renewed urgency, though Smith is 61. 

Dimon, who battled throat cancer in 2014, has been at the helm of JPMorgan Chase for 15 years, steering it through the 2008 financial crisis.

Dimon, with his signature silver hair, is one of the best-known and most-influential voices in the American business community.

President Donald Trump reportedly approached him for the treasury secretary position in 2016.

After his cancer diagnosis, JPMorgan Chase's board of directors made finding Dimon's successor a priority.

JPMorgan Chase is the largest US bank both in terms of assets and profits, with a record net profit of $34.43 billion in 2019.