Stephen Green, the chairman of HSBC, is being widely tipped to become the coalition government's new trade minister.Reports this morning suggested his appointment could be confirmed within 48 hours and possibly this afternoon.The government has been keen to recruit a high profile trade supremo to help British firms overseas and the capture of Green would be seen as a major coup, especially as reports previously suggested he had turned the job down.Green has been chairman of HSBC since 2005 and also chairs the British Bankers' Association.His departure from HSBC, however, could spark more speculation about the bank's HQ and whether it will stay in the UK. Last week, Stuart Gulliver, the head of HSBC's investment banking business and a possible future chief executive of the bank, told a conference it could leave London if ordered to split its investment bank from its retail lending operations.