DESCRIPTION: Hyattsville-based bank holding company for Suburban Trust Co., the largest bank in the Maryland suburbs of Washington and fourth-largest in the state, as well as Thurmont Bank in central Maryland and suburban Bank in Hancock and Hagerstown and leasing and mortgage subsidiaries (OTC). 1979 PROFITS PER SHARE: $3.38. LOANS: $937.4 million. DEPOSITS: $1.233 billion. DIVIDENDS: $7.7 million ($1.65 a share including an extra dividend of 25 cents a share). FOUNDED: 1915. TOP EXECUTIVES: Robert Tardio, chaiman and chief executive officer of the holding company and Suburban Trust Co.; H. Lee Boatwright III, president of STC.

Along with all other Americans, Suburban's management is trying to figure out where interest rates are going to peak. With the prime rate at 20 percent, the current structure of interest rates probably will contract the company's profit margins on lending somewhat in 1980. Tardio says the local economy is fairly healthy. "If we have a short recessionary period and if we can get that by us, we should continue to have a fairly strong performance in 1980," he adds. Suburban currently is talking merger with Maryland State Bank, which has two offices on the Eastern shore -- Bishopville and Salisbury.