With the Commonwealth Bank's chief executive officer Ian Narev about to step aside for CEO-in-waiting Matt Comyn, the pair have announced further changes to the senior executive team via a statement to the ASX.Narev is clearing his desk ahead of Comyn assuming the CEO role on 9 April, while: Melanie Laing, group executive human resources; Kelly Bayer Rosmarin, group executive institutional banking and markets; and David Whiteing, group executive enterprise services and chief information officer, will all leave the bank "in the coming months".Narev positioned the moves as an inevitable leadership transition, "part of a time of change as executives reassess their own plans, and the Bank prepares for its future." Comyn said he had commenced the search processes for replacements for the positions. He said a global search for his own soon to be vacated position of group executive retail banking services was "progressing well". Laing, appointed group executive human resources in 2012, has given notice of her intention to retire and will leave CBA by the end of the 2018 calendar year. Bayer Rosmarin has been with CBA since 2004, and has been group executive institutional banking and markets since 2013. She will leave the bank next month.George Confos, currently executive general manager business and corporate finance, will take acting responsibility for the institutional banking and markets division while a global search is undertaken for Bayer Rosmarin's successor.Whiteing, who joined CBA in September 2013, will also step down in April 2018. Paul Newham, currently executive general manager group operations, will take acting responsibility for the enterprise services division during the search for Whiteing's successor, the bank said.