Merrill Lynch’s losses in the past 18 months amount to about a quarter of the profits it has made in its 36 years as a listed company, according to Financial Times research that highlights the extent of the global banking crisis.

Since the onset of the credit crunch last year, Merrill has suffered after-tax losses of more than $14bn as its balance sheet has been savaged by almost $52bn in writedowns and credit-related losses.