AXA Asia Pacific Holdings Ltd chairman Rick Allert has reminded shareholders that the $13.29 billion takeover proposal by National Australia Bank Ltd (NAB) is by no means a done deal even though he and independent directors had agreed to the offer.

NAB became a surprise bidder for wealth manager AXA APH‘s Australian and New Zealand assets last week. The bid trumped an earlier proposal from AMP Ltd and France’s AXA SA, the majority owner of the target.

“It is important to understand that the NAB proposal is subject to a number of significant conditions,” Mr Allert said in a letter to shareholders on Tuesday.

In particular, AXA SA would need to agree to buy AXA APH‘s Asian assets from NAB under similar arrangements the French life insurance giant had with AMP for the deal to go ahead, Mr Allert said.

AXA SA has an exclusivity arrangement with wealth manager AMP that is in force until February 6 or when AMP chooses to terminate it.

AMP said last week that the exclusivity arrangement gave it time to consider carefully its position.

Mr Allert said also that NAB had to complete due diligence on AXA APH.

For Melbourne-based NAB, the deal would make the bank the nation’s biggest superannuation and retirement income provider and funds manager.

It would also consolidate its position as Australia’s biggest life insurer.

A winning bid by the AMP would make it the biggest super provider and enable it to better deal with the competitive pressure being applied by the major banks and non-profit superannuation providers.

NAB is offering AXA APH shareholders either cash, or cash and scrip for their shares.

The all-cash offer is $6.43 a share, while the mixed offer is 0.1745 of a NAB share plus $1.59 cash per share.

The mixed offer would value AXA APH at $6.16 a share based on Tuesday’s share price.

By 1441 AEDT, AXA APH shares had declined four cents to $6.49, suggesting investors are hopeful that there will be a further bid from AMP.

AMP shares fell six cents to $6.48 and NAB gained 18 cents to $26.18.

AMP and AXA SA increased their offer on December 14 to $1.92 cash per AXA APH share, from $1.38, as well as 0.6896 of an AMP share.

The revised offer, which was rejected by AXA APH‘s independent directors, would value the Melbourne-based company at $6.39 per share, just below NAB‘s all-cash bid.

AMP had said the bid that was its final and best offer and set a deadline of December 21 for from AXA APH to reply to the offer.