Minority shareholders in First American Bank of Maryland, who own 28 percent of the bank's stock, have been offered $42 a share for their holdings by the bank's parent, First American Bankshares Inc. of Washington.

The holding company, which owns the rest of the Maryland bank's stock, already has control of the First American banking subsidiaries in the District and in Virginia. The buyout offer would allow the holding company to complete its ownership of its banks in the Washington area.

The buyout, involving 454,000 shares held by 860 stockholders, would cost more than $19 million.

The shares of the thinly traded stock of First American Bank of Maryland have been available at $33 to $34 a share for about six months, said Patrick C. Ryan, chief trader at Johnston, Lemon & Co. Inc. in Washington. The stock rose to $39 on news of the $42 buyout, he said.

The $42-a-share offer for the Maryland stock is only slightly more than the bank's $38.61-a-share book value, for a premium of 8.8 percent. Book value, generally defined as the difference between a company's assets and liabilities, is often used to measure the value of a takeover.

While a shareholders meeting is required to vote on the proposal, the holding company has enough votes to force the buyout.

First American Bank of Maryland, with headquarters in Silver Spring, has assets of $1.074 billion. First American Bankshares, which is owned by Middle Eastern businessmen, has assets of $9.2 billion and operates 279 banking offices.

A similar proposal last year to buy out minority shareholders at the First American Bank of Virginia set off a confrontation between the bank's management and minority stockholders, who contended that the buyout price -- also $42 a share -- was too low. The premium in that case, based on a $33.30 a share book value, was 26.1 percent. The unhappy shareholders took their protests to court in Fairfax County, but they were unable to either stop the deal or boost the price.

Paul G. Adams III, president of First American Bank of Maryland, said the offer from the holding company was being considered by a committee made up of members of the Maryland bank's board. Adams said the committee was planning to hire an appraiser to get an opinion on the value of the stock.

The offer from the holding company included a letter from Keefe, Bruyette & Woods of New York, a bank analysis firm, supporting the $42 price. Adams said he favored the buyout and knew of no specific opposition. However, he said, "I'm sure there will be groups that will disagree." Such a disagreement could be decided by the state banking commission.

Under Maryland law, dissident stockholders can ask for a neutral appraisal of the value of a bank's stock. That "appraisal right," which was not available in Virginia, could become a key difference between the Virginia and Maryland buyouts if Maryland shareholders challenge the company's offer.