Alstom and Bombardier on Tuesday signed agreements with China's railways ministry to speed up development of rail transport in the vast country and also in overseas markets, the companies said.

French engineering group Alstom said it had signed a "long-term cooperation agreement" with the ministry to develop inter-city and high-speed trains as well as signalling equipment for China and "defined international markets".

"China is a strategic market for our transport activities, due to its size and its high growth potential," Alstom chief executive Patrick Kron said in a statement.

Separately, Canadian industrial group Bombardier also signed a memorandum of understanding with the ministry to step up development of "various products and systems" in high-speed rail for the Chinese and overseas markets.

The agreements are not binding. However China is rapidly expanding and upgrading its railway network amid increased pressures on its transportation system.

Railways Minister Liu Zhijun said Tuesday that the country had the world's longest high-speed network, at 7,531 kilometres (4,670 miles), state media reported.

The railway authority said in July that China would spend about 120 billion dollars to nearly double the country's high-speed rail network by 2012.

China has been accused of wanting to close its rail industry to foreign manufacturers and of profiting from stealing their technology -- charges it has denied.

Alstom Transport chief executive Philippe Mellier last year reportedly called for a boycott of Chinese-made trains, claiming the country blocked bids from foreign manufacturers.

"The (Chinese) market is gradually shutting down to let the Chinese companies prosper," Mellier said in an interview with the Financial Times.

"We're starting to see Chinese companies answering tenders around the world with Chinese freight locomotives, some of them being based on transferred technology."