* Class action seeks reparation for financial harm
* Uber denies it operated illegally
* Size of claim to be determined in court or settlement (Updates Uber comment)
SYDNEY, May 3 (Reuters) - A law firm filed a class action against Uber Technologies Inc UBER.N on behalf of thousands of taxi and chartered drivers in Australia, accusing the world's largest ride-hailing company of operating illegally and harming them financially.
The lawsuit, filed on Friday at the Victoria Supreme Court by law firm Maurice Blackburn, was brought on behalf of about 6,000 drivers and taxi licence owners from across four Australian states, the lawyers said in a statement.
"This will be a landmark case regarding the alleged illegal operations of Uber in Australia and the devastating impact that has had on the lives of hard-working and law-abiding citizens here," Andrew Watson, Maurice Blackburn national head of Class Actions, said in a statement.
An Uber spokeswoman said the company had not been served with a class action claim and denied it operated illegally.
"Uber denies this allegation and, if a claim is served making it, the claim will be vigorously defended," she said in an emailed statement.
"We will continue our commitment to delivering a great experience to Australians in all the cities where we operate."
The damages being sought could be "in the hundreds of millions of dollars", but would be determined as part of the case or settlement negotiations, a Maurice Blackburn spokesman said.
Uber has proved popular with the Australian public, even in the face of resistance from the taxi industry and local authorities.
The lawyers allege Uber knew its operations in Australia were illegal for a number of reasons, including that it "adopted a policy to operate in any market where the regulator had tacitly approved doing so by failing to take direct enforcement action."
The loss-making ride hailing firm is planning to list in the United States at a valuation of up to $91.5 billion in an initial public offering.