The Australian Competition and Consumer Commission announced on Thursday that it is still against National Australia Bank's (NAB) proposed takeover of AXA Asia Pacific Holdings Ltd, effectively throwing out the suitor's latest revised undertakings.

In a statement released by the competition watchdog, ACCC deputy chairman Peter Kell said that "the proposed undertakings offered by the parties do not provide sufficient certainty that the ACCC's competition concerns will be addressed."

The ACCC has earlier rejected NAB's acquisition bid of $13.3 billion for AXA APH citing serious concerns for the merger's impact on the industry's healthy competition environment.

The agency said that despite the adjustments submitted by NAB and following its careful evaluation, it is maintaining its opposition on the proposed buy out deal, arguing that the merger would mostly lead to considerable weakening of competition in the relevant retail investment platform market.

NAB and AXA had earlier put forward undertakings that would see the divestiture of the contentious North platform administration services offered by AXA APH, with both entities agreeing to sell it to IOOF Holdings Ltd.

Industry players, however, voiced out their opposition as they argued that the submitted undertakings could not adequately insure that a merged NAB-AXA entity would foster the needed competitive environment for retail investment platform offerings of both the two firms and other key industry providers.

Also, the ACCC noted that the proposed undertakings depended too much on IOOF's supposed ability "to provide an effective competitive constraint upon existing key players in the foreseeable future," adding that too much risks would be involved when third parties were being relied upon to perform specific obligations.