Serco's chairman Alastair Lyons has resigned from the troubled British outsourcing company.Lyons, who has been chairman since 2010, said while his colleagues asked him to stay it was his intention to step down once a new strategy and direction for the business were in place."I am, therefore, taking the necessary steps to ensure an orderly process for my own succession during the first half of 2015," he said in a statement.His resignation comes after the group revealed that profits for 2014 were expected to be reduced by £20m and lowered its forecast for 2015.Serco also announced £1.5bn in writedowns due to the loss of contracts. It comes amid an investigation into a scandal for overcharging on contracts for tagging criminals."Since the events of last year, I have sought to stabilise Serco with strong new management and non-executive directors; a much improved relationship with the UK Government; and clarity as to our strategic direction," Lyons said."The contract and balance sheet review, the reassessment of the group's future prospects, and the creation of the right capital structure are all necessary steps in putting Serco back onto an even keel and giving our new management team the basis for taking the company forward again."He said the initial findings of the review point to strategic and operational "mis-steps" at Serco for which he takes "ultimate responsibility".Lyons added that it was the right move for Serco to find a new chairman.Serco shares fell 0.4p or 0.2% to 211.6p at 08:54 in London.