Many US companies on Wednesday asked travel agencies not to book their staff on flights using Boeing’s 737 Max 8 passenger jets, reported Financial Times.

A business travel management agency said, “Some clients have expressed an interest in exploring the possibility of temporarily restricting travel on the Boeing 737 Max 8 aircraft," adding that this could lead to fewer flight options and make travellers “susceptible to higher airfares, depending on the route”.

The agency also said that it was working with clients to understand the “practicality and the implications of putting such restrictions in place," the report said.

A senior figure at a second global business travel group said, "A small number of large clients are asking for the aircraft type to be blocked from any future bookings”.

The companies making the requests were “household names” and the person said they “would not be surprised if it begins to build momentum," the report added.