Citigroup shares rose sharply in after hours trading in New York on Tuesday after Edward Lampert, the hedge fund manager who controls Sears Holdings, disclosed he had built an $800m stake in the world’s largest financial services group.

In a regulatory filing, an affiliate of Mr Lampert’s ESL Investments, said it had amassed the holding over the last year leaving it with 15.2m shares, or about 0.3 per cent of Citi’s stock, at March 31.