United Continental Holdings has changed its policy on employee travel and will now ensure crews riding on its aircraft as passengers are booked at least 60 minutes before departure, according to a statement from the company.

The change, issued on Friday, came after the backlash created by a video showing a United passenger being pulled from his seat and dragged down the aisle after refusing to leave an April 9 flight to make room for an airline employee.

The passenger, David Dao, suffered a concussion, a broken nose and two lost teeth, according to one of his lawyers on Thursday. Attorney Thomas Demetrio said Dr Dao would "probably" sue.

A hearing scheduled on Monday was cancelled after United and the city of Chicago agreed to Dr Dao's request to preserve and protect evidence, Mr Demetrio's office said on Saturday. A filing last week asked a judge to require the airline and city to preserve surveillance videos, crew lists and other information.

Bump passengers

United crews previously could be booked on flights until the time of departure. The change will allow employees to bump passengers, if necessary, in the gate area to avoid what happened on Dr Dao's flight: forcing passengers to leave their seats after they already boarded the airplane, said Maggie Schmerin, a United spokeswoman.

"This ensures situations like Flight 3411 never happen again," she said.

Bumping passengers is permitted by the US Department of Transportation as long as airlines provide some compensation - typically a voucher for future purchase - and a seat on a later flight. If there aren't enough volunteers, airlines can pick passengers - on United, those who paid more for a ticket or fly frequently are less likely to be selected.

United initially said Dr Dao's flight, from Chicago's O'Hare International Airport to Louisville, Kentucky, was overbooked, and its staff picked passengers to be bumped. But the airline later said it needed to make room for its own employees to keep other flights on schedule.

PR fiasco

United is reacting to pressure from the public-relations fiasco that blew up after the video spread on social media. Chief executive Oscar Munoz initially called Dr Dao "disruptive" and "belligerent" and apologised only for the need to "re-accommodate" him, but later struck a more contrite tone in a nationally televised interview.

Competing airlines are taking note of the controversy and making changes of their own. Delta Air Lines increased the payouts its airport agents can offer passengers on overbooked flights to $US2000 from $US800, according to a memo seen by Bloomberg.

While United is modifying its policy when it comes to booking its own crew, it didn't say if the policy of overbooking flights would be changed. The company said it was conducting a full review, and would announce the results by April 30.

Bloomberg