Proposals for Northern Rock Due

Prospective bidders are due to submit their final proposals Friday for mortgage lender Northern Rock, Britain's biggest casualty of the global credit crisis.

Richard Branson's Virgin Group, U.S. private equity house J.C. Flowers and investment firm Olivant Advisers have all publicly expressed varying degrees of interest in the bank.

However, none of the three have provided full financial details of their offerings ahead of the Friday deadline set by Northern Rock, and analysts will be watching closely for their proposals to deal with the mortgage lender's growing debt to the Bank of England.

Northern Rock shares fell 1.6 percent to $2.72 in early trading Friday on the London Stock Exchange as investors waited to hear the possible plans.

Virgin has so far proposed an equity injection that would see the struggling company kept intact and re-branded as Virgin Money.

J.C. Flowers has named a proposed high-profile management team for the bank, including Paul Myners, the former chairman of retailer Marks & Spencer, as chairman, if a deal is agreed on.

Olivant said its proposals would involve the immediate introduction of a team of its own executives into Northern Rock, and the subscription of a minority stake in the company.

Media reports have said that Apollo Management, Blackstone Group , Lone Star, and Cerberus Capital Management are also interested in making an offer.

Troubled Mortgage Lender

Northern Rock ran into trouble in September because of its heavy reliance on short-term money markets for funding. Its subsequent profit warning and appeal to the Bank of England for an emergency loan led to the first run on a British bank for almost a century.

The rush was only stemmed days later when the government stepped in to guarantee deposits of Northern Rock savers.

British Treasury chief Alistair Darling has warned Northern Rock that it has only "a matter of weeks and months" to sort out its future.

The existing loan facility from the central bank comes to an end in February, and while Darling said that was not a "drop-dead date" for the bank, he told lawmakers earlier this month that it could not carry on indefinitely.

Northern Rock effectively has three months to agree to a deal with a buyer, during which the government will allow the bank to draw credit against all its assets.

However, analysts have suggested that none of the bidders will be able to repay the estimated $47 billion that Northern Rock has already borrowed from the Bank of England under the emergency loan facility by the end of the government's strategic review in February.

They are expected instead to request an extension to guarantees on deposits provided by the central bank.

Northern Rock obtained a High Court injunction earlier this week barring further publication of a confidential memo prepared for potential bidders after The Financial Times on Tuesday published excerpts from the memorandum, prepared by Northern Rock's advisers -- Merrill Lynch , Citigroup and the Blackstone Group.

Northern Rock said further publication of the memo could "jeopardize the complex discussions and negotiations taking place in connection with its strategic review."