Chinese stock investors are shouting "mayday" now that a shipping company with a fleet of oil tankers is about to become the first state-owned enterprise to delist from a domestic exchange.

But Nanjing Tanker, also known as Changjiang National Shipping Group, is expected to sink in two weeks without the Chinese government bailout that many stock investors have been demanding.

Last month, authorities let investors take a hit when Chaori Solar Energy became the first bond issuer to default on an interest payment in China.

Nanjing Tanker's demise is a sign that the Chinese government is apparently no longer willing to keep every inefficient, money-losing state company afloat for the sake of jobs and investors.

The communist government's long-time emphasis on maintaining "social stability" -- that is, keeping workers employed and investors happy at any cost -- has prompted bailouts in the past. In January, for example, a state bank was apparently among the unnamed financiers that rescued a coal mine trust product from impending default for the sake of 700 retail investors.

Beijing's social stability policy may have played into a Nanjing Tanker decision late last year to expand its fleet by buying 20 crude oil carriers, including supertankers, despite years of losses.

The company, a division of the state cargo shipping conglomerate Sinotrans & CSC Holdings, reported losing 5.9 billion yuan -- nearly US$ 1 billion -- in fiscal 2013. Its customers have included oil giants Exxon Mobil(XOM_), Royal Dutch Shell(RDS.A_) and Sinopec(SHI_).

Government officials said nothing about a possible bailout after the company filed for permission to delist from the Shanghai Stock Exchange in January, a move that could take effect April 23.

Nor did a rescue plan emerge after the company filed for bankruptcy. The official Securities Times newspaper said a Shanghai court launched proceedings last week by notifying the company's creditors, including Chinese suppliers and Japanese bond holders.

Also significantly, policymakers didn't flinch after 20 of Nanjing Tanker's 149,000 common stockholders held a rare street protest on March 31 outside the Shanghai Stock Exchange building.

State media, which did not report the rally until a week later, said the unhappy shareholders included blue-collar workers and a university economist. They gathered peacefully, the report said, and held a banner reading "Protect Small Investors."

Protesters were quoted as saying they fear total loss and oppose the company's delisting plan. They also want trading in company stock, which has been suspended since last May at 1.53 yuan a share, to resume as soon as possible.

The company has been in the red since 2010, losing 754 million yuan in 2011 and 1.2 billion yuan the following year.

Despite the financial woes, the trade magazine SinoShip said in last December that Nanjing Tanker's Singapore division had unveiled plans to buy 20 ships -- 10 VLCC supertankers and 10 medium-range oil tankers -- from 18 separate ship owners for $467 million.

"Nanjing Tanker said the move will help the company lower operating costs to deal with the current crisis," the report said.

At the time of publication, the author held no positions in any of the stocks mentioned.