ABN Amro's chief executive has said the takeover bid from Barclays is too low to be recommended to shareholders.
ABN is still not recommending either offer
Rijkman Groenink was speaking at a meeting of shareholders called to discuss bids from Barclays and a group led by Royal Bank of Scotland (RBS).
Barclays' part-cash part-shares offer is currently worth about 59bn euros ($83bn; £41bn) while the RBS mostly-cash offer is worth 70bn euros.
RBS is bidding with Fortis and Banco Santander Central Hispano.
"The offer of Barclays is too low. We cannot ask shareholders to pay the difference from the consortium's bid," Mr Groenink said.
But he did not go as far as to endorse the consortium's offer.
ABN's previous position was that Barclays' offer was more consistent with its own strategy and history even though the RBS-led consortium's offer was worth more.
The shareholders meeting is a chance for investors to get information about the offers ahead of the expiration of the Barclays and RBS offers on 4 and 5 October.
Whichever bank wins it will be the biggest financial takeover in history.
RBS passed a major obstacle on Monday when the Dutch finance minister and central bank said they would not block the takeover.
The consortium still needs full approval from the European Union, which said on Wednesday that it had cleared the RBS and Santander parts of the offer and was still considering the Fortis part.
Fortis said that the EU's objections relate to the market for small and medium enterprises in the Netherlands, and said it had presented "remedies" that it expected would allow the deal to go through.