United Silent On CEO's Medical Condition

United Airlines declined to provide details about the medical condition of its new chief executive on Sunday, days after the airline said Oscar Munoz was admitted to hospital.

The 56-year-old's health problems come barely a month after Munoz took on the job of improving the profitability and reputation of United, the No. 2 US carrier by capacity.

A spokeswoman for United said by email on Sunday morning that it did not have an update to share yet.

United had acknowledged in a short statement on Friday that Munoz's family informed the company he had been taken to hospital the day before, and said it would provide "further details as appropriate."

A person familiar with the matter confirmed that he had suffered a heart attack.

United has an obligation to disclose material developments, wrote John Coffee of Columbia University's law school, in an email. "It is the obligation of the company to keep the market informed of material developments and this seems clearly material to me," Coffee wrote.

It is puzzling why the company has not stated who will take over for Munoz in the meantime, said Greg Taxin, chief investment officer of New York-based Luma Asset Management.

"It's probably silly or foolish that they just haven't satisfied people's desire to know how the chain of command is working," Taxin said. "On the other hand, I presume the CEO of United Airlines goes on vacation on a regular basis, and he's not around to answer questions or make decision and things run just fine."

United's previous chief executive left while US federal authorities were conducting an investigation involving the Port Authority of New York and New Jersey.

Munoz had made it a priority to tackle complaints by customers and employees of United in recent years, often related to the company's struggles to merge the operations of the former United and Continental airlines.