Financial General Bankshares Inc., the Washington bank holding company that is beset by a struggle for control, yesterday reported a 26 percent increase in operating income that gave it record first quarter earnings.

Financial General said is earned $2.78 million (44 cents per share) for the three months ended March 31 For the same period in 1977 the company earned $2? million from operations plus an extraordinary tax credit of $428,000 that procome of $2.63 million (42 cents per share).

The 13-bank holding company reported its total assets increased 13.4 percent, from 1.6 billion to $1.8 billion, while loan volume grew a similiar percentage, from $808 million to $914 million.

The Financial General banks showed a 9.1 percent increase in total deposits, which grew from $1.41 billion to $1.54 billion.

Communications Satellite Corp. reported first quarter profits of $7.75 million (97 cents a share) on revenues of $42.23 million.

The Washington firm's performance in the same period last year produced earnings of $9.9 million (98 cents a share, with more stock outstanding) from revenues of $41.95 million.

Comsat said the difference of $1.94 million in quarterly profits resulted primarily from an upward adjustment in the 1977 period because of changes in accounting policies.

The figures also reflect terms of a proposed settlement of a dispute with the Federal Communications Commission, involving international rates.

Although net operating profits climbed $570,000 from the same period last year, other income declined by more than $1 million because of an accounting change related to the proposed FCC settlement.

A subsidiary, Comsat General Corp. reported first-quarter profits of $2.8 million compared with $1.5 million in the same period last year as revenues increased to $16.1 million from $15.2 million.

Comsat's directors approved the second quarterly dividend at the increased rate of 50 cents a share, payable June 12 to stockholders of record May 12.

First & Merchants Corp., the Richmond banking company, reported a slightly lower net income but a 7 percent gain in earnings before securities transactions for the quarter ended March 31.

Income before securities transactions increased from $2.1 million (64 cents per share) to $2.26 million (69 cents per share) while net earnings fell from $2.09 million (64 cents) to $2.07 million (63 cents).

First & Merchants reported total loan activity increased 10.8 percent to $1.1 billion; total assets increased 2.5 percent, from $1.85 billion on March 31, 1977 to $1.89 billion this year.

United Services Life Insurance Co., the Washington firm that specializes in insurance for military and government workers, yesterday reported its first quarter profits grew from $1.6 million (53 cents per share) to $2 million (64 cents per share).

Total income increased from $13.7 million to $14.8 millions, with new business amounting to $929,000, up 30 percent, said Leslie P. Shultz, president.

The company said its assets have increased 8.3 percent in the past year to $329 million, and it now has $2.82 billion of insurance in force, counting a $36 million increase during the first quarter.

Tesdata Systems Corp of McLean, reported first quarter earnings of $417.000, up six percent from the $393,000 reported in the same period a year ago; income increased 27 percent from $3.2 million to $4.1 million.

Earnings per share declined from 38 cents to 33 cents because the company's public stock offering last April increased the amount of stock outstanding.

President Thomas E. Stone said the quarterly earnings were 10 to 12 percent below projections, largely due to delays in major orders.