Insurer ING has denied speculation that it is sizing up competitor AIG New Zealand for a takeover.

This comes as AIG staff have been circulated emails in the form of a memo on how a takeover might affect them.

But AIG claimed the email was a hoax and it would not comment on market rumours or hoax correspondence.

In a written statement, chief executive David Pierce said the company would communicate with stakeholders directly if it had anything to announce.

A spokeswoman later said the company had conducted forensic checks on the email system to establish how the hoax occurred.

Meanwhile, ING marketing manager Steven Giannoulis said he had no knowledge of any such transaction. “It’s not pending or right on the go at the moment.”

But AIG New Zealand is a sitting target as the company’s international parent, NYSE-listed American International Group, evaluates its business amid massive writedowns.

American International Group fell to a 13-year low on the sharemarket this week, after pessimistic Credit Suisse analysts forecast the company would lose up to $US6.5 billion this quarter on mortgage related writedowns in one  of its divisions.

In May, Standard & Poor’s downgraded the insurer to an AA- rating after it posted two straight quarters of losses.

AIG lost more than $US18 billion over the last three quarters due to investments tied to subprime mortgages, Forbes reported.

In contrast, AIG’s New Zealand operations received a solid AA+ report from Standard & Poor’s in May.