A major Chinese property company has suspended offshore debt payments, deepening turmoil in the beleaguered sector.

Sino Ocean, which says it's one of the nation's top 20 real estate developers, said in a stock exchange filing Friday that it would temporarily stop making payments on US dollar-denominated bonds, and suspend trading of them, as it embarked on a wider debt restructuring.

The company said it made the decision as it faces "mounting liquidity pressures" due to a sales slump across the wider industry since 2021, which has hampered its ability to repay its debts.

So far this year, "the group has experienced a rapid decline in contracted sales and increased uncertainty in asset disposals," it noted.

"The group respectfully requests that creditors allow the group some time to resolve the current liquidity issue and work with its advisers to formulate a plan."

Sino Ocean, which is based in Beijing, focuses on residential and commercial development, and has some 600 projects across more than 80 cities in China, including high-end office buildings and shopping malls.

The developer and its financial and legal advisers, Houlihan Loukey and Sidley Austin, did not immediately respond to requests for comment on how long the restructuring process might take, whether its onshore debt payments would be affected and what legal implications it may face.

Shares of Sino Ocean plunged 10.6% in Hong Kong on Friday following the announcement, to just 59 Hong Kong cents (about 8 US cents).

As of June, the company's total current liabilities, or debt coming due within a year, had reached nearly 60 billion yuan (approximately $8.4 billion), according to its interim annual report.

News of its troubles adds to greater concerns over China's property sector, which have come to the fore in recent weeks as Country Garden, the nation's largest homebuilder last year, flirts with the possibility of default. Last month, the developer also suspended trading of some of its bonds, citing a need to consider restructuring its debt.

On Friday, data from the National Bureau of Statistics showed property investment in China fell 8.8% in the first eight months of the year, compared to the same period a year ago. Property sales by floor area dropped 7.1% in the January to August months, compared to the first eight months of 2022.

On Thursday, Moody's downgraded its outlook for the overall sector, citing a downturn in residential sales and continued jitters about the health of the industry.

In June and July, nationwide property sales fell around 20% compared to the same period a year before, it said in a report.

This reversed "the 11.9% growth for the first five months, reflecting renewed weakness in residential property," the agency added.

"Lower-tier cities, particularly in weak economic regions, will bear the brunt of the expected sales decline amid continuing population outflow, while demand in [major] cities will be more resilient."

Moody's also downgraded the holdings of another Chinese real estate developer, China SCE Group, to junk on Thursday, saying it also had "sizable" debt and cash flow problems. The group's ratings have been bumped down from B3 to Caa1.

— CNN's Juliana Liu contributed to this report.