AIB has been named as a possible target for Spain's largest bank, Santander, which the 'Financial Times' reported yesterday was looking for further expansion abroad, especially in Europe.
The paper said it was citing sources "familiar with the matter".
AIB's share price immediately perked up 55c, going on to close 30 cent (1.6pc) up at €19.20 on the speculation which, although still very much a rumour, was not being ruled out by banking analysts yesterday.
From Santander's standpoint, the Irish group's UK commercial banking operations - which account for just under 20pc of profit - would complement Abbey National, which Santander acquired under two years ago, but which is more heavily engaged in retail banking.