The United Kingdom's biggest insurer, Aviva PLC, is in talks to buy US life insurer AmerUs Group Co., valued at about $2.4 billion, in a deal that would boost Aviva 's undersized presence in the booming US market, claims a recent report on Reuters.

Aviva, whose bid for UK rival Prudential P.L.C. was rebuffed in March, has long said it wants to expand in the United States, the world's biggest long-term savings market.