Aviva, which trades in Britain as Norwich Union, admitted yesterday that it could be interested in making an American acquisition - while denying a report that it had "tabled" a £1.6 billion bid for AmerUS of Iowa.

"Aviva confirms that it has not made such a proposal and no discussions with AmerUS are taking place," it stated.

"In line with its strategy for growth in the international long-term savings market, Aviva continues to review value-driven inorganic growth opportunities in the major global long-term savings markets."

A spokeswoman commented: "There are three key areas - Europe, Asia and the US - presenting roughly equal opportunities. The key to anything is that it has to deliver value to our shareholders.

"To say we have tabled a bid is inaccurate. It is untrue. We haven't made a proposal."

Aviva has never commented on persistent rumours last year that it tried and failed to negotiate a merger with Prudential.

Its existing American offshoot, Aviva USA in Boston, employs 350 people and manages funds of £2.6 billion.

By contrast, Aviva has leading market positions in many European countries. It generates about half its profits overseas - and nearly twothirds of its life profits.

Aviva USA reported life and pensions sales of £393 million in the third quarter of 2005, up 54 per cent from a year earlier. The spokeswoman described it as a "small niche business".

It was claimed that Aviva had offered $74 cash for each AmerUS share, 19 per cent above its closing price of $62.20 on Tuesday. Unnamed sources said it might have to raise that to $80 to secure an agreed deal.

The report linked Aviva's interest in the Iowa company to the retirement after 31 years in charge of Roger Brooks, chairman and chief executive of AmerUS.