ANC Rental Corporation in the USA confirmed that the UK and European operations of ANC International were specifically excluded from the Filing for Chapter 11 following the announcement last week.
In the UK, the ANC brands of National Car Rental, Alamo Rent A Car and Guy Salmon are trading in line with expectations.
Chapter 11 was begun by a voluntary petition by the firm and begins a brief block on legal action from creditors, allowing a breathing spell for a rescue plan to be considered.
The National Car Rental brand is represented in 70 countries. In October, the UK firm denied it would be affected by the crisis affecting its parent, following a collapse in demand caused by the September 11 terrorist attacks in America.
ANC said the Chapter 11 filing would make no difference to customers, who would continue to be serviced without interruption throughout the world.
It added that all existing and future reservations will be honoured. John Leigh, senior vice-president and general manager, pan-Europe, said: 'I have spoken to suppliers and customers to explain we are unaffected. Service levels will be maintained.'