Three area banking firms have reported a sharp increase in profits during the first three months of 1978.

American Security Corp., owner of the second largest D.C. bank, reported yesterday that operating profits rose nearly 10 percent to $4.4 million ($1.83) in the first quarter compared with $4 million ($1.67) in the same period last year.

Including gains from selling securities, American Security net income was $4.45 million ($1.83) compared with $4.42 million ($1.82).

Chairman Carleston M. Stewart said the higher earnings from bank operations reflected a loan volume in the recent quarter that averaged more than $250 million above the same three months during 1977.

Citizens Bank & Trust Co. of Maryland reported first-quarter profits of $1.9 million ($1.55 a share) compared with $1.35 a share in the 1977 period.

Deposits of the Riverdale-based bank rose 4 percent to $452 million and loan volume increased nearly 9 percent to $288 million.

American Bank of Maryland, a Fiannicial General Bankshares institution based in Silver Spring, reported its fifth consecutive quarterly earnings gain following a period of depressed profits in 1975 and 1976.

First-quarter operating earnings were $369,817 (49 cents a share compared with $131,092 (17 cents) in the 1977 period, according to President G. J. (Bud) Manderfield. Deposits on March 31 were $139 million, a gain of 16 percent from the same period a year earlier.

Directors approved a cash dividend of 15 cents a share, payable April 14 to owners of record March 31.

Hotel Investors, a Kensington real estate investment trust that specializes in hotel properties, reported profits for the six months ended Feb. 28 rose to $1.1 million (74 cents a share) from $927.299 (60 cents) in the same period a year ago.

Second-quarter profits rose to $531, 460 (28 cents). Hotel Investors said the recent gains reflected improved operations of the firm's Tallahassee Hilton and Dallas Marriott hotels, with the latter showing benefits of an expansion last year.

Directors delared a regular payout of 42 cents a share on May 2 to owners of record April 17.

Ryland Group, a Columbia-based home builder, reported a 44 percent decline in earnings for the first quarter of 1978. Profits were $460,000 (18 cents a share) compared with $823,000 (31 cents) in the 1977 period. Sales rose to $23 million from $21 million.

Chairman James P. Ryan and President Robert J. Gaw attributed the first-quarter decline to fewer sales than expected beacuse of adverse weather conditions that extended production schedules and overhead costs.