MNC Financial Inc., the area's biggest banking company, must pay back $375 million today to a group of bank creditors headed by J.P. Morgan & Co. unless the banks decide to extend the payment deadline, giving MNC a much-needed reprieve from its debt obligations.

The cash-strapped parent of American Security Bank and Maryland National Bank has been furiously selling off assets to pay back creditors, but as of Friday it did not have enough money to pay back J.P. Morgan and also pay off $271 million in long-term notes that mature tomorrow.

If MNC defaults on one of those payments, it could be forced into bankruptcy, a move that would prompt an immediate takeover of its subsidiary banks by the federal government.

On the other hand, if MNC can demonstrate to J.P. Morgan and its other bank creditors that it is "making progress toward the sale" of remaining assets, J.P. Morgan could decide today to extend the repayment terms and even advance the ailing bank company more credit.

MNC has been racing against the clock to sell its prized credit-card subsidiary, a move that would provide enough cash to pay off the parent firm's debt and shore up American Security's and Maryland National bank's capital, the financial cushion that protects the federal deposit insurance fund from losses.

To date, however, MNC has been unable to sell the subsidiary to a private buyer and an alternative plan to raise money by selling stock in the operation has yet to take final shape.

Last month, MNC hired the investment banking firm Goldman, Sachs & Co. to handle the stock sale, but as of Friday, the bank company had not filed final plans for the deal with the Securities and Exchange Commission, as anticipated.

According to a preliminary outline of the deal, MNC Chairman Alfred Lerner and Progressive Co., Lerner's Cleveland insurance firm, would buy up to 30 percent of the credit-card-subsidiary stock. However, the Federal Reserve, the agency that must approve such a purchase, had not received an application for the deal as of Friday, a Fed spokesman said.

Nevertheless, sources said Goldman Sachs still intends to present the stock offering to investors at meetings this week.

Rampant selling by investors nervous about MNC's future sent the bank company's stock sliding once again Friday, down $0.625 to close at $2.12 1/2. The battered stock had traded as high as $23 a share in the past year.