The report didn’t say where in the US the flight was headed.
The hospital’s Michelle Simard said that, according to the family’s press agent, the actress was no longer in Canada.
“We have no information on Ms Richardson’s health condition, but the family should give more information by tomorrow.”
Richardson was hospitalised after falling during a private lesson on a beginners trail at the famed Mont Tremblant ski resort on Monday. IrishCentral.com reported the Tony Award-winning actress and wife of actor Liam Neeson suffered a head injury.
Richardson, 45, is the elder daughter of Oscar-winning actress Vanessa Redgrave and the late director Tony Richardson, and belongs to a British acting dynasty.
“We know she has had an accident but we really do not know any more details,” said Kika Markham, who is married to Richardson’s uncle, Corin Redgrave. “We are very concerned.”
Mont Tremblant said Richardson fell on a beginners trail and later reported not feeling well.
“She did not show any visible sign of injury but the ski patrol followed strict procedures and brought her back to the bottom of the slope and insisted she should see a doctor,” said a statement from the resort, which is about 128km north-west of Montreal.
The resort said the instructor and a ski patrol accompanied Richardson to her hotel, where they again recommended she should be seen by a doctor.
Resort spokeswoman, Catherine Lacasse, said Richardson at first said she was fine.
“An hour later she said she didn’t feel well. She had a headache, so we sent her to the hospital,” Ms Lacasse said. “There were no signs of impact and no blood, nothing.”
An ambulance was called and Richardson was later transferred to Hopital du Sacre-Coeur in Montreal.
Producers confirmed that Neeson immediately left the Toronto set of his upcoming movie Chloe for Montreal, a publicist for the film said in an e-mail.
Richardson’s films include Gothic, A Month in the Country, Nell — in which she appeared with her future husband — The Parent Trap and Maid in Manhattan.
Trained at London’s Central School of Speech and Drama, Richardson has had extensive stage experience in the West End and Broadway.
She won a Tony Award in 1998 for playing Sally Bowles in Cabaret.
Her maternal grandparents were the actors Michael Redgrave and Rachel Kempson, and her uncle Corin and aunt Lynn Redgrave are also both actors.
Sister Joely Richardson is also an actress, best known for starring in the TV series Nip/Tuck.
In January, Richardson and her mother played the roles of mother and daughter in a one-night benefit concert version of A Little Night Music, the Stephen Sondheim-Hugh Wheeler musical, at Studio 54 in New York.
She married Neeson in 1994, and the couple have two sons.