Aviva's merger with Friends Life will see 1,500 staff removed out of the combined workforce of 31,500 people.
It is expected the merged company will save £225m a year by the end of 2017.
Aviva has published details of the proposed merger with Friends Life, which will be voted on by Aviva shareholders on 26 March 2015.
Aviva shareholders will own 73% of the enlarged company while Friends Life shareholders will own 27% of the company.
If the merger is approved meeting the merger will be effective from 10 April 2015 and the shares will be traded on the London Stock Exchange on 13 April 2015.
A statement from Aviva said: "This acquisition is financially and strategically compelling. It will increase our cash flows, reduce our leverage and support continued growth in our dividend.
"It also secures our leadership position in our home market and gives greater flexibility to drive growth in other parts of the Aviva group.
"As a result of this transaction, Aviva expects to deliver approximately £225 million of annual savings by the end of 2017. This may result in a reduction of approximately 1,500 roles from across the enlarged Aviva Group of approximately 31,500 people.
"We appreciate that this news may be disconcerting for employees and we would look to ensure that any redundancies are kept to a minimum wherever possible, by using vacancies and natural turnover, for example.
"At this stage, no specific teams, roles or locations have been identified as the proposed transaction has not completed. When we are clearer on this, following completion of the deal, we will fully engage and consult with employees and their representative bodies."