Communications Satellite Corp. reported a 16.9 percent drop in profits for the 1980 first quarter yesterday, a loss the company said was based on start-up costs for a new venture and cuts in revenues from a government program.

Comsat's profits dropped during the first quarter to $9.88 million ($1.24 a share) from last year's $11.9 million ($1.49) for the same quarter.

Comsat is a partner in Satellite Business Systems with Aetna Life & Casualty and International Business Machines Corp. SBS, a communications firm, plans to launch itss first satellite this year.

In another earnings report. First American Savings and Loan Association has reported a drop in profits and deposits for the first quarter of the year.

First American, with offices in Woodbridge, Manassas, Virginia Beach and Fredericksburg, said first quarter profits were $147,924 (49 cents a share) down from $160,859 (53 cents) during last year's first quarter.

Deposits dropped by $476,000 during the quarter, compared to an increase of $5.6 million during the first quarter of 1979.

James H. Harrison, the S&L's chief executive officer attributed the eight percent profits drop to the institution's cost of funds and used the opportunity to call for cutbacks in government spending and regulation.

"The free enterprise system that made this country great is at stake," Harrison said."Economic freedom, personal freedom and political freedom are inextricably linked. To have one, you must have all."

Bank of Columbia, N.A. reported a 79 percent increase in first-quarter profits to $134,862 (31 cents a share) up from $75,202 (17 cents) for the first quarter last year.