SYDNEY (Reuters) - China Evergrande's ( EGRNQ ) liquidators have hired three law firms to advise on the troubled property giant's winding-up process, according to sources with direct knowledge of the matter.

Global firm Clifford Chance and Hong Kong firms Tanner De Witt and Karas So were mandated recently to provide legal advice on the liquidation, which has been under way for about six weeks, the people added.

Alvarez and Marsal (A&M) Managing Directors Tiffany Wong and Eddie Middleton were appointed liquidators by a Hong Kong judge on Jan. 29, bringing an end to more than 18 months of negotiations between the firm and offshore bondholders.

The Guangzhou-based firm was considered the world's most indebted developer with more than $300 billion of total liabilities both onshore and offshore.

But Evergrande was ordered to be liquidated after it had been unable to offer a concrete restructuring plan more than two years after defaulting on its offshore debt and following several court hearings.

The sources could not be identified discussing confidential information.

Karas So, which operates in association with London-headquartered firm Mishcon de Reya, declined to comment.

Wong and Middleton, A&M, Clifford Chance and Tanner De Witt declined to comment.

Evergrande did not respond to a request for comment.

Lawyers working on the case will look for, among a number of issues, evidence of wrongdoing and negligence across the company, its management and external advisers that could have led to Evergrande defaulting on its debt, the sources said.

Evergrande's liquidation could last for more than a decade, according to some offshore investors, and become a blueprint for future major Chinese corporate winding up processes.

The pace of Evergrande's liquidation would rely on whether mainland Chinese courts recognise the Hong Kong judgment. Recognising the ruling would allow creditors to seize unpledged onshore Chinese assets, a process that could take a number of years to complete, according to lawyers.