By Chris Dorrell Adrian Sainsbury, boss of merchant bank Close Brothers, has taken a “temporary medical leave of absence” from the business. In a statement to the market, the bank said it has put in place “robust temporary cover arrangements” to ensure continuity in the delivery of the group’s strategy during this period. Mike Morgan, group finance director, will assume Sainsbury’s primary responsibilities while chair Mike Biggs and other members of the senior management team will support. The bank said it would provide a further update “in due course”. Its full year results will be announced …