Lloyds Banking Group, which owns Scottish Widows, has reportedly been seeking a buyer for the business for a while, according to The Sunday Times.
Talks about a possible deal are expected to begin this week, senior City sources told the newspaper.
Both companies have declined to comment.
First announced in March, Standard Life and Aberdeen’s merger was overwhelming approved by shareholders on Monday.
The £11bn ($14.1bn, €12.6bn) deal needed the support of 75% of Aberdeen’s investors and 50% of Standard Life’s.
More than 95% of Aberdeen and 98% of Standard Life shareholders voted in favour of the merger, which will be named Standard Life Aberdeen.
Following completion of the deal, which is expected in mid-August, Standard Life shareholders will own 66.7% of the combined group, while Aberdeen shareholders own 33.3%.
This reflects Aberdeen's £3.8bn market capitalisation and Standard Life's £7.5bn value.
The combined company will be run by co-chief executives Martin Gilbert (Aberdeen) and Keith Skeoch (Standard Life).
At an analyst and investor conference when the deal with Aberdeen was announced, Skeoch was asked whether Standard Life was moving away from life assurance and towards becoming an investment house, reports The Scotsman.
He said: “We are – yes, you are right in terms of becoming more of a world-class investment company than a life assurer. I would argue this is a process that was put in place about 13 years ago.”