A number of high-profile accounting firms with operations in China are trying to reach an agreement with United States securities regulators on access to audit documents, according to a regulatory filing.

The filing on Monday by the US Securities and Exchange Commission (SEC) announced a 90-day extension period that pushes a hearing on a pending appeal to Sept 19 from June 23. The SEC and representatives from the "Big Four" US accounting firms agreed that the extension "would facilitate the parties' continued settlement efforts".

Five companies - a group that includes the US' Big Four - have been involved with the SEC's enforcement division on the case for several years. The case stems from the accounting companies' not providing access to information related to specific Chinese clients that are listed on US stock exchanges.

The Chinese branches of the Big Four - Deloitte Touche Tohmatsu CPA, Ernst & Young Hua Ming LLP, KPMG Huazhen and PricewaterhouseCoopers Zhong Tian CPAs - and BDO China Dahua CPA have been under investigation by the SEC since December 2012.

US officials have been trying to get documentation from the Big Four for years to investigate accounting scandals that have hurt US-listed Chinese companies. The accounting firms have denied US requests for financial documents because of strict Chinese laws regarding such types of information.

US SEC Administrative Law Judge Cameron Elliot decided in January that the four accounting agencies' operations in China were in violation of the Sarbanes-Oxley Act. It requires all foreign accounting firms, upon request, to produce "audit work papers and all other documents" on US-listed companies for the SEC's review.

In the decision, Elliot recommended that the Big Four be suspended from auditing US-traded companies for six months. Without audited financial statements, a company is not allowed to sell securities in the US.

The judge also censured Dahua but did not recommend a suspension for the Beijing-based accounting firm. Dahua was previously a member of BDO International, the world's fifth largest accounting group.

The firms announced a plan for an appeal shortly after Elliot's decision was handed down, arguing that they were trapped between US law, which requires them to hand over any documents regulators request, and Chinese law, which prohibits transferring data that might contain state secrets to foreign parties.

If the SEC's ruling stands, it could leave more than 100 US-listed Chinese companies without an auditor.

Katura Hudson, a spokeswoman for PwC, confirmed the information from Monday's regulatory filing, but said she could not comment further.

Deloitte, KPMG and the SEC could not be reached for comment. Ernst & Young declined to comment.

The five companies involved in the case have a total of 103 US-traded companies that they audit or which they helped audit, according to their 2013 annual reports filed with US regulators.

KPMG Chairman Michael Andrew told Reuters in January that there is a clear "need for both governments to resolve the impasse".

Jim Doty, chairman of the Public Company Accounting Oversight Board (PCAOB), the top US audit watchdog, has said he is optimistic the two sides will be able to reach an agreement this year to inspect the audit work of firms registered with the PCAOB but based in China.

Paul Gillis, a professor of accounting at Peking University in Beijing and author of the China Accounting Blog, said that the Big Four in China have been on a slump since 2008.

"[Last year] was a tough year for the Big Four, especially on the regulatory front with Chinese, Hong Kong, and US regulators all zeroing in on them," Gillis wrote in a May 31 blog post titled, Bad News for the Big Four in China.

"Local firms grew 14.5 percent in 2013, their slowest growth in a decade," he wrote. "The Big Four managed only 2.8 percent growth in China, well below the growth in China’s GDP."