They said the central government may put a limit on individuals' overseas investments, also known as the 'through train' scheme, amid concern that a flood of money from mainland stock markets would destabilise the world's fastest-growing economy. 'All signs are that it will be some time before the overseas investment programme will materialise,' one source said. 'The central government is reassessing the policy and will likely draft more detailed guidelines.'

A China Banking Regulatory Commission spokesman told Hong Kong Cable TV investors should calm down and not believe rumours the programme was in jeopardy. 'Everything is being processed and the reports that we're against the programme are sheer rumour,' the spokesman said.

However, the Hong Kong market slid yesterday as investors took profit amid reports of the delay. The Hang Seng Index had surged to a record last week on optimism that billions of dollars would flow to the city from the mainland under the scheme.

The State Administration of Foreign Exchange (Safe) said on August 20 that mainland residents could invest an unlimited amount in Hong Kong stocks under a pilot scheme at the Bank of China's (BOC) branch in Tianjin's Binhai economic zone.

The move, designed to ease excessive liquidity in the mainland and give people a wider choice of investments, was expected to boost Hong Kong-listed mainland companies, known as H shares. H shares currently trade at a massive discount to their A-share counterparts listed in Shanghai or Shenzhen.

But the BOC branch in Tianjin is awaiting the go-ahead from the China Banking Regulatory Commission (CBRC), fuelling speculation Beijing may be poised to make an about-turn on the policy.

'There are conflicting views on how the individual investor programme should develop,' said Jing Ulrich, JP Morgan's chairman of China equities. 'Some parties are concerned that the A-share market will be negatively impacted.'

Hong Kong's financial secretary, John Tsang Chun-wah, said the mainland authorities were still studying details of the plan, and Hong Kong residents should be patient in waiting for the scheme.

Insiders said the China Securities Regulatory Commission (CSRC) and several other government departments were putting up obstacles, as they feared a flight of funds to Hong Kong would hurt buoyant A shares.

'We can't comment on the issue because the policy wasn't drafted by us,' a CSRC official in charge of information said yesterday. 'You should raise the question with Safe and the CBRC.'

The People's Bank of China and the upper tier of Safe were eager to direct funds out of the mainland and strongly advocated launching the 'through train' programme, the insiders said.

But Caijing magazine reported that during a financial working conference organised by the State Council recently, top leaders began to become more cautious. They were also wary about risks of runaway investment in Hong Kong, sources said.