Commonwealth Bank is set to embark on a deep cost-cutting program likely to include branch closures, the axing of hundreds of middle managers and the sale of more international businesses.Detail about the aggressive attack on expenses is expected on 8 August when chief executive Matt Comyn will update the market on the organisational restructure.The CBA boss yesterday unveiled his plan to "simplify" CBA's operating model by formally separating the wealth management and mortgage broking arms from the group's core banking businesses.All of the bank's financial advice, asset management and mortgage broking assets will be spun into a new holding company known as CFS Group that will be demerged from the bank in 2019.Comyn's public rhetoric reflects the new mantra of an organisation that has a "focus on our core banking businesses in Australia and New Zealand".This is a clear signal that the bank will follow ANZ in selling its Asian retail banking units, particularly its extensive network in Indonesia that has struggled to turn profits over the last decade. CBA is also expected to follow its three major Australian rivals with a local branch-culling program later this year.The Hayne inquiry has exposed CBA's management as one of the most bureaucratic in the local banking market and Comyn's simplification agenda is a portent of a clean out of middle management roles.The new CBA chief will rely on a fresh lineup of senior executives to implement the change program.Only a handful of former CEO Ian Narev's management group has survived Comyn's executive cull, with two external appointments announced on Monday including former ANZ executive Nigel Williams to the paramount role of chief risk officer. A big winner in Comyn's executive revamp is former chief risk officer David Cohen, who takes over as deputy CEO.Cohen has been charged with responsibility for implementing the wealth management demerger and co-ordinating the bank's engagement with government, regulators and community groups.Other winners in the management shake-up are Angus Sullivan who has been confirmed as the head of retail banking operations and Andrew Hinchcliff who takes the reins of the institutional bank from the start of August.CBA is now undergoing a transformation analogous to the strategic overhaul announced last week by Telstra chief Andy Penn.Both companies are trying to streamline product distribution by simplifying management reporting lines and offloading large chunks of their businesses.Both also have a similar problem: the market is not (yet, at least) buying into their respective remedies.CBA's share price tanked after Comyn's announcements on Monday, sliding A$1.70 or 2.3 per cent to $72.16.It was a negative day for most banking stocks but CBA's decline was more than double the losses posted by its three banking peers.One analyst, who requested not to be identified, said the failure of the bank to follow through on a previous announcement to list its Colonial asset management arm was a key driver of the share price underperformance.The decision to abandon the initial public offering has extinguished the prospect of a special dividend to CBA shareholders, he said.There was also