The independent firm would be “free from profit-making incentives and constraints”, the firms said.

They said their aim was to provide care to staff at a “reasonable cost”.

Nonetheless, the announcement sparked fears that tech giant Amazon could disrupt the healthcare sector in the same way that it has the retail sector.

The firms are the three largest private employers in the US, collectively employing over 500,000 staff.

The three companies said they would focus on technology to provide “simplified, high-quality and transparent healthcare”.

“Our people want transparency, knowledge and control when it comes to managing their healthcare,” said Jamie Dimon, chairman and chief executive of JPMorgan Chase.

“The three of our companies have extraordinary resources, and our goal is to create solutions that benefit our US employees, their families and, potentially, all Americans.”

Shares in US health insurers UnitedHealth, Anthem and Cigna Corp all fell over 5% in early trading following the announcement.