John Hanson Savings and Loan announced yesterday that it has refused an offer to be acquired for $28 million, or $12 a share, by Baltimore Bancorp, a Maryland bank holding company.

In a terse, three-paragraph statement, directors of the S&L, which is based in Greenbelt, said they will proceed with a public offering next week that is expected to raise $15.6 million, or $6.50 a share -- less than half the money stockholders would have received under the Baltimore offer. Cancellation of the sale was a condition of the Baltimore offer.

Hanson said that it turned down the offer just 72 hours after receiving it because a majority of Hanson shareholders said they intended "to vote against" the proposed merger.

Harry Robinson, president of Baltimore Bancorp, said: "I'm amazed. We don't understand the logic of it.

"I recognize the great position in the company stock is owned by the officers and directors and their families," he said. "But the other stockholders should be considered. They have a chance to make $12 a share right now rather than $6 or $7 next week."

He would not comment on whether Baltimore would try to take over Hanson when it goes public next week.

Hanson directors would not comment on why they refused the offer.

Officers and directors control 29.5 percent of Hanson's stock. In addition, Walter L. Green, the company's general counsel, owns 27.3 percent, making him the S&L's largest shareholder.

"Any merger would require shareholder approval," Charles Dukes, chairman and chief executive of Hanson, said in a prepared statement. "Since holders of a majority of our shares have expressed opposition to the company's pursuing [the] merger . . . it would be futile for the company to proceed with negotiations."

Hanson has $600 million in assets and 23 branch offices along the Eastern Shore of Maryland and in the suburbs surrounding Washington and Baltimore.

Baltimore Bancorp, whose primary holdings are the Bank of Baltimore and the Municipal Savings and Loan Association, has $2.1 billion in assets and 30 branch offices.