Citigroup has tapped the capital markets for the second time in nine days, launching a $3bn (€2bn, £1.5bn) equity offering aimed at bolstering its balance sheet and capitalising on investor appetite for battered financial stocks.

Citi’s move, which follows last week’s issuance of $6bn in preferred shares, sent its stock down more than 2 per cent in after-hours trading – a sign of investor worries that holdings will be diluted by the new offering.