Industry commentators say Aviva could set its sights on arch-rival Prudential, which is still recovering from its failed $20bn takeover of AIG's Asian business.
The Guardian understands Aviva would be keen to target Prudential's UK arm for takeover if its rival opts to break itself up by demerging or selling its British, Asian and US operations.
Aviva chief Andrew Moss previously said the company is only interested in making bolt-on acquisitions, but industry sources say the company would now look at Prudential's UK business if it was made available.
One senior executive said: "Moss would be unwilling to pass up an opportunity to buy Prudential's British business - valued at more than £5bn - which could be merged with Aviva's UK interests. But the price would have to be compelling to make Aviva reverse its current tack of expanding in Europe, where Moss views growth as more promising."
However, some analysts say many of Aviva's shareholders would oppose a merger with Prudential's UK business because the British market is "capital-intensive and growing too slowly, if at all", according to Barrie Cornes, insurance expert at Panmure Gordon. "But that could change if it was going for a knock-down price."
It is understood Moss would not sit back while competitor Resolution, headed by Clive Cowdery, acquires Pru for a bargin price.
Speculation is rife Pru UK is Cowdery's next target after Resolution last week agreed to acquire Axa's life insurance assets for £2.75bn, the Guardian reports.
Aviva declined to respond to the Prudential rumours with a spokesman saying: "The scenario is hypothetical and we are not prepared to comment."
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