The firm effectively controls about 51 percent of Aviva NDB Insurance, a listed insurer, where the other key shareholder is Sri Lanka's NDB Bank group.
"The sale of our stake in Aviva NDB is an example of further progress towards narrowing the group’s focus, as we concentrate on fewer business segments where we can produce attractive returns with a high probability of success," John McFarlane, chairman of Aviva plc said in a statement.
Aviva NDB Insurance had been trading around 430 rupees a share in Colombo valuing it around the price paid by AIA group.
"The sale price reflects the relative success and growth of the Aviva NDB business. We’re pleased to be selling this business to a strong and committed player in AIA Group, who is well positioned to take the business forward," statement.