China says it badly needs the electricity the dam will generate

The shares - available only to Chinese buyers - should go on sale next week, with the proceeds used to pay for the massive generators which began generating electricity earlier this year.

The flotation, which aims to raise 9.83bn yuan ($1.2bn; �700m), was meant to start in September but was delayed because regulators felt there were already too many share sales stacked up that month.

Even so, news of the date for the public offering impacted markets in China, with the Shanghai composite index edging down 0.33%.

There is little doubt that the shares will sell out several times over.

But the project remains controversial.

In sheer size it dwarfs other dams, creating a reservoir which when full will be 600 kilometres (375 miles) long and 175 metres (574 feet) deep.

There have already been worries about the quality of building, with cracks appearing even before power generation began.

Many villages and towns - and even some small cities - along the banks of the densely populated Yangtze have already been submerged by the rising waters.

More than 600,000 people have been forced to relocate, some as far away as Shanghai, 1,000 km (600 miles) east. About 1.3 million people will eventually have to move.

Many environmentalists have also warned about the danger of soil erosion, as well as pollution caused by trapped sewage and industrial waste.

China's leaders say the country needs the 180bn yuan (US$22bn) dam to produce electricity, as well as control the annual flooding of the Yangtze.