China will likely allow some of the world's top 500 companies to float shares in its A-share market as it prepares the launch of an international board in Shanghai, Chinese media reported on Tuesday.

After considering the views of many parties, the regulator has come to the conclusion that the international board should first consider companies on the world's top 500 list, the China Securities Journal reported on Tuesday, citing a source it described as authoritative.

But the report said that the authorities haven't decided whether red-chip companies - domestic companies that are registered overseas - will be allowed to list on the international board.

A press officer at the China Securities Regulatory Commission told China Daily on Tuesday that there is still no timetable for the launch of the long-awaited international board and the delay may be caused by the lack of agreement among higher-level officials and concerns of the Hong Kong Stock Exchange, a potential competitor of the Shanghai bourse in the market of new share sales.

Some government departments believe that the board should focus on the red chips in the initial stage while others wanted the board to focus on the world's top multinationals, according to industry players.

Local media reported earlier this month that China's securities regulator may allow about 10 foreign companies in the first batch of listings on the international board.

The 10 companies will comprise multinational corporations such as HSBC Holdings PLC and Unilever PLC, as well as foreign-incorporated Chinese firms such as China Mobile Limited and China National Offshore Oil Corp, the 21st Century Business Herald reported, citing a government proposal.

Foreign companies looking to list in Shanghai must have a market capitalization of at least 30 billion yuan ($4.6 billion) and a combined three-year net profits of at least 3 billion yuan, according to the proposal.

The companies must have posted a net profit of at least 1 billion yuan in the most recent 12 months, the proposal said.

China has long said it plans to open its stock market to foreign listings because it wants to raise the global profile of Shanghai, which aims to become an international financial center.

The government also hopes the board will broaden investment channels for its swelling yuan savings.

There had been constant speculation about an immediate launch of the international board since 2009.

Fang Xinghai, director-general of the Shanghai Financial Services Office, said late last year that the city government was hoping to launch the board in 2011.

Rules for the international board are largely ready, although no timetable for its launch has been set, Geng Liang, president of the Shanghai Stock Exchange, said in March.