The market value of the company rose in the wake of a report in a Dutch newspaper that it had hired Goldman Sachs and JP Morgan to act in an advisory capacity for a strategic review.
Dutch daily Het Financieele Dagblad said that the change of direction could see ING merge with a Dutch bank or could result in overseas acquisitions.
Since the article was published shares in Fortis, KBC Group and Dexia have all posted gains of three per cent, as speculation mounts that they will prove targets for ING's activities.
Peter Jong, ING spokesman, said: "We don't feel pressure to take on large acquisitions, but if there is consolidation, we will participate."
News of the move from ING comes at a time when the proposed merger between ABN Amro and Barclays could leave the bank facing a new rival with vast assets in the Dutch market.
ING has a market value of $93 billion dollars.