Motorcyclist critical after Sydney crash

A motorcyclist believed to be in his 20s is fighting for his life in hospital after colliding with a car in Sydney's west.

A CareFlight chopper flew to the crash at Tregear on Friday morning, with a specialist emergency doctor and intensive care paramedic both working to stabilise the man.

The rider, who has suffered critical head injuries and fractures to his legs, was taken by ambulance to Westmead Hospital where he remains in a critical condition, an ambulance spokeswoman said.

The driver of the car was also taken to hospital with minor injuries and is in a stable condition.