Chinese stocks extended their losses from last week and sank to a five-month low on Monday amid lackluster economic data and fears that the flood of new listings that will soon hit the market will stretch liquidity.

The benchmark Shanghai Composite Index fell 1.8 percent to 2,045.71 points, the lowest level since Aug 2.

Important gauges of the manufacturing and service industries fell in December, triggering doubts about the prospects for China's economic growth and its stock market performance this year.

On Monday, HSBC Plc's service sector Purchasing Managers' Index fell to 50.9 in December from 52.5 the previous month.

But State-owned oil and gas giants PetroChina Co Ltd and Sinopec Ltd cushioned the index's fall by rising more than 1 percent each in the last minutes of trading, said Zhang Qi, a Shanghai-based analyst at Haitong Securities Co Ltd.

The increases came after the Oriental Morning Post reported on Monday that the Chinese securities regulator urged blue chip companies to start a "capitalization management" process to reverse the recent market losses.

The Shanghai Composite Index has lost more than 7 percent since Nov 30, when the China Securities [Hong Kong Company Formation, Incorporation, Business Registration]Regulatory Commission released a reform plan for the nation's IPO mechanism and promised to end a 15-month IPO hiatus this month.

Investors are also selling because they are afraid that the IPOs will take funds away from existing shares and depress the market, analysts said.

"Market sentiment is at a low point and will remain so this week, as investors wait to see what the IPO resumption will do to the market," said Zhang.

Twenty-seven companies had started IPO procedures as of Jan 5, part of the first batch of 50 IPOs expected in January.

Eleven of those companies are now in the middle of their roadshows and initial pricing operations, while the rest have released their IPO prospectuses.

Neway Valve (Suzhou) Co Ltd and Anhui Yingliu Electromechanical Co Ltd are slated for a listing on the Shanghai Stock Exchange, while the other 25 companies will go public on the Shenzhen Stock Exchange.

The securities watchdog said on Nov 30 that it would allow at least 50 companies to float shares this month after[Hong Kong Company Formation|Hong Kong Company Registration] releasing a plan mapping out reforms for the nation's IPO market. At the moment, more than 760 candidates are waiting to be listed. The regulator said it will take almost a year to assess them all.

PricewaterhouseCoopers forecast that up to 300 companies will float shares this year, raising a total of 250 billion yuan ($41 billion).

In a statement posted on Monday on the CSRC's website, the watchdog's Chairman Xiao Gang vowed again to better protect individual investors. He also promised to raise dividends and keep issuing prices in check and to punish firms guilty of irregularities. He added that protecting investors is the watchdog's top priority.

In light of the recent CSRC policies to crack down on artificially high issuing prices, PricewaterhouseCoopers predicted that price-to-earnings ratios will fluctuate in a range of 20 to 40, from a high of about 100 in the pre-reform era.

However, some still feel that the CSRC is not doing enough.

"As a stock market investor, I'm very disappointed," said Xin Yu, president of the Guangzhou-based Zequan Investment Co Ltd.

Xin added that investors' rights still mainly exist on paper.

It's true that the regulator has issued guidelines to boost supervision on information disclosure and to crack down on fraud and insider trading, but the fundamental issue of the market is that it's still too easy for the firms backing the IPOs to cash out, Xin added.