Mr Moss announced his departure from the firm earlier this month and executive deputy chairman John McFarlane is currently working in the role.
The firm said it would be searching all over the world to find the best person available for the role.
It also revealed it would be undertaking a strategic review to ensure the firm was ‘focused on the right segments’ - which could lead to more job losses.
This would involve putting plans in place to advance Aviva’s performance and shedding staff who ‘are not part of our future’. This would be reviewed in June.
Mr McFarlane said: “My first task is to make an improvement in the capital and financial strength in the group as well as an improvement in our financial performance.
“Whilst not underestimating the significance of the challenge I am optimistic of the outcome.”
Within this review, a programme to improve profit and value would reallocate capital across the firm’s various businesses to improve operating margins and return. It could also lead to Aviva stopping business in some areas.
The firm also revealed its interim results for the first quarter of 2012.
Long-term saving sales were down five per cent to £7.5bn but pension sales increased by 12 per cent from £1.12bn to £1.26bn.
Protection sales were up 20 per cent from £250m to £300m but individual annuity sales were down from £645m to £641m.