Belgium felt the full force of the credit crunch as fevered selling gripped shares in Fortis, prompting the Belgo-Dutch bank to issue a fresh denial of market rumours about its financial position.

Fortis is among Europe’s hardest-hit casualties of the financial crisis. The bank has struggled to regain the confidence of investors in spite of announcing measures to strengthen its capital base by €8bn ($11.6bn) in June, and ousting its chief executive, Jean-Paul Votron, the following month.