The US government is poised to take a 34 per cent stake in Citigroup, increasing both its exposure to and influence over, the troubled financial group following Sunday’s completion of a long-awaited $58bn share offering.

The move is a milestone in a financial crisis that has forced the US authorities to come to the rescue of some of the largest institutions in the country. Citi has been a repeated recipient of government aid and is the only large surviving bank to have had to cede a shareholding to the government.