AMP says its $13 billion bid for Axa Asia-Pacific Holdings (Axa APH) is “far from complete”, while rival suitor National Australia Bank (NAB) may challenge the competition regulator’s move to take it out of the race.

Speaking at a Macquarie Securities conference in Sydney last week, AMP CEO Craig Dunn said his company still needs to secure the support of Axa APH’s independent directors, who had plumped for NAB’s $14 billion merger offer.

While AMP is now the logical leader in the battle for Axa APH after the Australian Competition and Consumer Commission (ACCC) rejected a rival bid by National Australia Bank because it would lead to a “substantial lessening of competition”, NAB CEO Cameron Clyne said last week that his company “continues to pursue its options to obtain approvals for its proposed acquisition”.

Business commentators last week suggested the most likely options for NAB would be an agreement to divest itself of some investment-related assets or a court challenge.

Axa APH has advised its shareholders that if NAB doesn’t reach an agreement with the ACCC by May 31 – six weeks after the regulator’s decision was published – Axa APH can terminate the agreement with the bank.

“NAB and Axa SA can also do the same,” it said in the statement. “Axa APH will provide an update on the status of the transaction when it is available.”

Mr Dunn says AMP continues to believe it can put forward a proposal that the independent directors of Axa APH will be able to recommend to their minority shareholders.

Business commentators say AMP is likely to wait and see what NAB plans to do before it moves to sweeten its offer to the independent directors, probably by increasing the cash component of its bid.