Maryland's two largest savings and loan associations -- Baltimore Federal and Loyola Federal -- plan to branch into the stock brokerage business in January, spokesmen for the companies said.

The two Maryland firms, each with assets of more than $1 billion, are equity partners with 28 other S&Ls that have bought a brokerage service called Invest. The service will allow the S&Ls to operate Invest brokerage offices in their branches.

Through the Invest program, S&Ls will be able for the first time to offer stocks, bonds, mutual funds and investment advisory services to their customers.

Marshall W. Moore, a senior vice president at Loyola, said in published reports that some planning still is needed and that the company plans "to start out small with a steady expansion."

Loyola has 34 offices, and 10 to 20 percent of them eventually may have Invest centers, Moore said.

Baltimore Federal has hired John Roemer, a former stockbroker with Dean Witter Reynolds Inc., to oversee marketing the annuity plan that the firm has designed for customers with maturing All Savers certificates.

Each Invest center will have a registered representative of the New York Stock Exchange. Moore said Loyola will hire someone to fill that post, but the company plans to train its employes to handle the brokerage duties.

The centers, equipped with the electronic communications equipment a stockbroker needs, in most cases will be small offices in a company's office. The brokerage fees at Invest centers will be lower than at some retail brokers, a Baltimore Federal spokesman said.

"They will be there to help the customer who has a medium- to long-term investment objective," said Baltimore Federal's John Moran.

The salaries of Invest brokers will be paid by the savings and loan association, and their pay will not depend on commissions from stock trades, which is different from typical stock brokerages.

Loyola and Baltimore Federal have purchased a 40 percent interest in the venture. The 28 partners, distributed among most of the nation's larger markets, have about 1,500 branches and assets of close to $100 billion.

The Invest brokerage network was developed by four founding partners, including Perpetual American Federal Savings and Loan Association of McLean, the biggest S&L in the Middle Atlantic region; Coast Federal of Sarasota, Fla.; City Federal of Elizabeth, N.J.; and California Federal of Los Angeles. Invest's headquarters are in Tampa.