US financial stocks slumped to their lowest level since 1997 on Tuesday as the escalating global credit crisis forced the UK to announce the partial nationalisation of its banking system.

Gordon Brown, UK prime minister, agreed to inject £35bn-£50bn ($61bn-$88bn) into several of the biggest UK banks, after a crisis of confidence sent financial shares plummeting. RBS fell 39 per cent to add to a 20 per cent tumble the day before. Rival HBOS has fallen more than 50 per cent over two days.