Northern Rock said today that it is in talks with "a number" of potential suitors, but that discussions are at a "very early stage".
The statement by the troubled lender comes after a consortium led by Sir Richard Branson confirmed that it was among those interested in the Newcastle-based bank.
Northern Rock said today: "In response to recent press speculation, Northern Rock plc confirms that it is working with a number of potentially interested parties regarding proposals for a variety of potential transactions."
But Northern Rock, which said that proposals it had received so far had been "preliminary in nature", warned that there could be no certainty as to the outcome of the talks.
The company added that it did not expect to make a further announcement about the discussions on its future until a strategic review of the business had been completed.
On Friday the Virgin Group unveiled a rescue bid for Northern Rock, which has seen its share price plummet since it was forced to ask the Bank of England for emergency funding last month.
Northern Rock is the UK's most high-profile casualty of the global credit crunch, with news of the emergency loan having prompted the first run on a British bank in over 140 years.
Under takeover plans put forward by a Virgin-led consortium, which also includes AIG and American and Far East investors, Northern Rock would be rebranded under the Virgin Money name.
A statement from Virgin said it was committed to retaining the bank's business "in its entirety", but claimed that a complete rebranding was needed to restore consumer confidence in Northern Rock.
Reports name the US investment firms Cerberus and JC Flowers among other parties reportedly eyeing up Northern Rock.
Last week the government announced that it was extending a guarantee to protect the savings of Northern Rock customers. The Treasury said the decision to guarantee new savings deposited with the beleaguered lender, in addition to existing deposits, would allow the bank to "pursue the full range of its strategic options".