Citigroup is taking on some 3 million online banking customers with a £575 million acquisition of Prudential's Egg Banking business. The deal for the purely-online bank includes products and services including online payment and account aggregation services, credit cards, personal loans, savings accounts, mortgages, insurance, and investments, as well as use of the Egg brand.

The acquisition will give Citigroup in the UK more than 4 million customers and will quadruple its credit card base, adding Egg's 2.9 million card customers to its 800,000.

George Awad, chief executive of Citigroup Global Consumer Grou...