Standard Chartered, the emerging markets bank, surprised the stock market on Tuesday by saying it was raising £1bn to take advantage of increased activity by corporate customers wanting to expand in Asia.

The bank, which reported first-half pre-tax profits of $2.8bn (£1.7bn), up from $2.6bn in the same period last year, said the capital raising was an opportunistic move to strengthen its balance sheet so it could support corporate customers in Asia as they came out of the downturn.