MNC Financial Inc., which owns Maryland National and American Security banks, will not pay common and preferred stockholders a fourth-quarter dividend, the bank company said yesterday.

The Baltimore-based bank company lost more than $240 million in the first nine months of the year because of the deteriorating commercial real estate market, and it expects to report additional losses in the fourth quarter. Despite the mounting red ink, MNC had continued paying dividends on its common and preferred stock.

The only way a bank that is losing money can pay dividends is by dipping into its capital -- the cash and assets that are held in reserve to protect the federal deposit insurance fund from losses.

MNC's two bank subsidiaries are now short of the minimum requirements for capital and have signed special agreements with federal regulators indicating an intent to improve their capital levels.

In the third quarter, regulators declared that MNC could not pay future dividends without the approval of the Federal Reserve Board and the Office of the Comptroller of the Currency.

MNC officials said yesterday that future dividend payouts will be considered, depending on government approval and the bank company's performance.

MNC stock closed yesterday at $3.37 1/2, unchanged. The announcement about the dividend was made after the stock market closed. Signet Banking Corp. stock rose 37 1/2 cents to $10.37 1/2 yesterday after its board of directors declared the Richmond-based bank company's regular fourth-quarter dividend of 39 cents a share.