Mr Harvey has opted to take early retirement from the Norwich Union insurer in July this year after almost a decade as chief executive.
"With almost ten years as chief executive under my belt, there are other dimensions to my life and other things I want to achieve in both international charity work and the business world," he said in a statement.
The chief executive's decision to quit follows an unsuccessful Â£17 million merger attempt with UK rival Prudential in March 2006 and he will retire on a Â£500,000 a year pension.
Mr Harvey was in charge during the stock floatation of Norwich Union ten years ago and has also overseen the merger of the insurer and CGU in 2000, creating Aviva.
Mr Moss, 48, has previously worked at HSBC and Lloyds. He will be replaced as finance director by Philip Scott, currently head of Aviva's North American and Asian operations.