Belgian-Dutch banking giant Fortis was forced to deny rumours that it was experiencing liquidity problems as its shares took a battering for a fifth day in a row and reached their lowest level in 14 years on Friday.

"We underline the solid position of the bank," Fortis said in a statement released in Brussels and Utrecht.

"Fortis solvency is solid and well above the regulatory minimum," the bank said, noting that customer withdrawals represented "less than 3 per cent of its total retail and private banking customers assets" in Belgium and the Netherlands.

Shares in the company were down about 20 per cent by late afternoon trading in Brussels to 5.22 euros (7.63 dollars), their lowest level in 14 years.

Fortis ranks among Europe's top 20 financial institutions and is part of a consortium that took over Dutch bank ABN Amro.

Its troubles began in June, when the company said it needed to raise more capital and that it would stop paying out dividends.

On Friday, the company also said it would speed up the sale of some 10 billion euros in assets. Speculation about its liquidity and funding has prompted rumours that it might be taken over by rival banks such as France's BNP Paribas.

The Belgian government also moved to play down concerns that Fortis might become the latest victim of the global credit crunch by appealing for calm.

"We call on financial operators to be responsible and refrain from spreading false information," said Belgian Finance Minister Didier Reynders.

The Belgian government said it would also intervene to ensure that customers' money remains safe.