Shanghai-based Spring Airlines Thursday said its net profit in the first half of this year doubled to 160 million yuan ($23.58 million), and the company plans to list on the A-share market next year.

It is the first listing plan for a private carrier since the sector was opened in 2002.

"We have chosen the underwriter," said spokesman Zhang Wu'an, but refused to elaborate.

Spring Airlines is the only budget airline that survived in China amid closures due to cash flow dilemmas or peer pressure. It has sold tickets as low as 1 yuan ($0.15) to attract buyers.

Last year, the company saw a net profit of 158 million yuan ($23.28 million), as its capacity increased by 40 percent, and 95 percent of seats were occupied on average.

Although Zhang said "it should have no problem on cash flow," analysts warn that a limited scale of self-owned assets may be "a risk" for the carrier's listing.

"The carrier is short of self-owned aircraft, and the rental percentage is high in its fleet, so the assets it owns are limited," said Yao Jun, an industry analyst from China Merchants Secu-rities (CMS).

So far, Spring Airlines has purchased two aircraft for its fleet of 20, which it plans to expand to 100 by 2015.

Zhang Xiuzhi, CEO of Spring Airlines, said in an earlier interview that the number of purchased aircraft is expected to reach 30 percent by 2012, through financing and bank loans.

However, Chairman Wang Zhenghua said it would not be easy to achieve the goal, due to government approval difficulties, capital structure, and outside capital sources, reported the Securities Market on July 14.

Spokesman Zhang told the Global Times that normally it takes at least two years from order to delivery, and "the company can not wait".

Currently, the debt ratio of Spring Airlines is 70 percent, lower than that of State-owned carriers, such as 79 percent for Air China, 75 percent for China Southern, and 97 percent for China Eastern in April.

Moreover, Yao from CMS added that it remains hard for the privately owned Spring Airlines to expand due to the strength of the State-owned giants.

Song Weiya, analyst from Great Wall securities, agreed: "It is much easier to list if there is a State-owned background."