MNC Financial Inc., the parent firm of three of the region's largest banks, is considering the sale of certain profitable subsidiaries to meet a heavy demand for cash, sources close to MNC said yesterday.

The Baltimore-based parent of Maryland National Bank, Equitable Bank and American Security Bank, needs to pay off $100 million in short-term borrowings in the coming months and another $800 million in longer-term borrowings by the end of the year, sources said.

Under normal circumstances, the bank company would simply roll over its outstanding borrowings by selling new debt. However, concern about MNC's exposure to the weakening commercial real estate market -- reflected in a series of warnings about MNC issued by major credit rating agencies -- has made it impossible to renew the borrowings, forcing MNC to find alternative sources of funds, sources said.

MNC reported yesterday that it lost $74.7 million in the second quarter because of problems with commercial real estate loans. The bank company had projected a loss of that magnitude in a statement released earlier this month.

Although MNC's upcoming cash needs have raised concerns among some bond market professionals, none of its bank subsidiaries appears to be affected immediately. Sources said the assets that may be sold include only non-bank operations.

Analysts said they are confident MNC, which has $28 billion in assets, has the cash on hand to meet its short-term needs, but added that the company will be unable to meet the longer-term obligations without finding new sources of financing or selling assets.

"The short term is manageable," said Merrill Lynch analyst Mark Lynch. "And in the longer term, well, they've got time to figure something out."

Bank officials refused to comment on the situation yesterday, but sources said the problems follow a steady decline in the bank company's credit rating by Moody's Investor Service, which rates the degree of risk associated with corporate debt. Two weeks ago, Moody's said it considered MNC's short-term debt -- known as commercial paper -- and some of its long-term debt as "below investment grade," or the equivalent of "junk bonds."

Wall Street sources said the new ratings have made it impossible for MNC to sell new commercial paper and will prompt investors to demand repayment when the notes come due.

Sources said MNC's directors are meeting twice a week to map out a restructuring plan that would resolve the cash deficit. Options under consideration include selling off profitable subsidiaries, such as MNC's leasing operation and its commercial financing operation, both of which have been funded largely through the sale of commercial paper.

Another option being considered is the transfer of certain MNC operations from the MNC holding company to the bank subsidiaries. That way, they could be funded through bank deposits rather than through the sale of commercial paper and long-term debt. MNC already has transferred its mortgage company.

MNC's most profitable asset, its credit card operation, may also be restructured to help meet funding needs. However, analysts said it would be highly unlikely that the bank company would sell this operation.

"It's the family jewel," Lynch said. "If they did sell it, it would provide an instant cure to the problems. But it would also mean losing the only money-making operation they've got right now."

Sources close to MNC said the bank has been gearing up for the cash shortage for the past several months. The company stopped selling its commercial paper to large national investors, such as money market funds, about two months ago. It has already paid off about $300 million of maturing commercial paper to those investors and will pay out another $100 million in the next two months.

The rest of the debt coming due will be one-year obligations known as variable-rate renewables, most of which come due at the end of the year. The company began issuing this form of debt in 1988 to reduce its commercial paper holdings and to fund the holding company's short-term investments.

According to MNC's financial statements, about $823 million in variable-rate renewables will mature at the end of the year and during the first quarter of 1991. Sources said investors will demand repayment for most of that debt because of Moody's downgrading of the debt.

As the area's biggest real estate financier, MNC has been hit hard by the slowdown in that market. For the first six months of this year, MNC said it lost $68.5 million, compared with a profit of $124 million ($1.44 per share) in the first half of last year.

The company's nonperforming assets -- those not paying interest -- increased to $757 million at the end of the quarter, more than double the level of nonperformers as of March 31. More than half of its nonperforming loans are troubled real estate loans, the company said. Because of that increase, MNC said it added $233 million to its loan-loss reserve, the cash that bank owners provide to protect the federal deposit insurance fund from losses.

Analysts said it is unclear whether the losses will continue in the third quarter. The bank company is undergoing an examination of its loan portfolio by federal regulators. More than 50 examiners from the Office of the Comptroller of the Currency arrived last week to start the review, and analysts said yesterday the regulators could force further additions to reserves and more write-downs on the value of assets.

Further problems at MNC's banking subsidiaries could make it more difficult for the holding company to raise the money it needs, analysts said.

"The entire banking industry right now -- especially banks in the mid-Atlantic region -- has been under a lot of pressure in the marketplace when it comes to raising money," said Wayne Garnes, who follows MNC for Standard & Poor's Corp., another rating agency. "Any further deterioration would certainly add to that pressure."