Simon Machell, chief executive of Norwich Union's (NU) general insurance business, will be replaced in an overhaul of the Aviva group executive structure.

Machell will take up a post in Asia, leading Aviva's Asian and Australian businesses. He will be replaced by Igal Mayer, chief executive of Aviva Canada.

The overhaul will see Patrick Snowball, Norwich Union executive chairman, depart in July to join Towergate as deputy chairman.

The shake-up, the second in the past year, is thought to be part of changes incoming chief executive Andrew Moss is instigating before he officially takes on his role in July.

The insurance group said the changes reflected the "increasingly multinational nature of the group's businesses".

Philip Scott will become group finance director, a role vacated by Moss.

Scott is currently serving as executive director with responsibility for Aviva's operations outside Europe. He will retain his responsib-ilities for asset management, and continue to sit on Aviva's board.

Mark Hodges will remain as chief executive of Norwich Union Life.

Tidjane Thiam, chief executive, Aviva Europe, Anupam Sahay, group strategy and planning director, and John Ainley, group HR director, will continue in their current roles.

All positions will come into effect on12 July.