As it struggles with an investigation into its financial processes, Tesco has wrangled an earlier start for new finance director Alan Stewart, persuading current employer Marks & Spencer (M&S) to release him two months earlier than planned.Stewart, who had been on gardening leave recently after handing in his resignation from M&S in July, was not expected to start in his new role until 1 December, but will instead join Tesco with immediate effect, as the retail giant seeks to ride out its latest financial storm.On Monday the group suspended four senior executives following revelations that profits had been artificially inflated by £250m, with the stock market reaction wiping more than £2bn off the company's value."We have uncovered a serious issue and have responded accordingly," said new chief executive, Dave Lewis."We have asked four people, senior people, to step aside," Lewis said, adding that the action was "not disciplinary or an indication of guilt"."We will let the investigation determine whether any rules were broken and what I need to do to address that."Analysts heaped criticism on Tesco as news of the latest crisis begin to emerge."This is not the stuff of a well-operated FTSE-100 organisation," said Clive Black, analyst for stockbrokers Shore Capital, who added he was "flabbergasted" by the latest storm to hit the retail giant.