The world's largest bank, Citigroup Inc, said Friday its profits rose 18 per cent in the second quarter on strong international business and investment banking, according to dpa. The New York-based credit institution earned 6.2 billion dollars, or 1.24 dollars per share, in the quarter, up from 5.26 billion dollars, or 1.05 dollars per share, in the year earlier period. Chief executive Charles Prince attributed the record profits largely to the bank's business outside the United States, as Citigroup's international business profits rose 35 per cent to 3 billion dollars. The bank has invested billions in three recent international acquisitions, where business is expanding faster than in the US. Citigroup has also increased its share in the Japanese Nikko Cordial Corporation to 68 per cent.