For the second successive quarter, Government Services Savings & Loan Inc. of Bethesda announced a sharp decline in profits.

Earnings for the quarter ended Sept. 30 were $299,826 (35 cents a share), down from a record $821,263 (95 cents) in the second fiscal quarter in 1978.

Further, six-month earnings for Government Services were $595,565, compared with $1,476,443 for the same period last year.

Government Services, with four branches, had an increase in assets for the quarter, when compared to last year, from $314 million to $335 million, although savings accounts dropped to $270 million from $274 million one year ago.

Alexander R.M. Boyle, president of Government Savings, said the decline in profits was in large part due to the company's loss of savings.

In other reports, Capital Mortgage Investments reported an unaudited loss of $28,795 for the quarter ending Sept. 30, compared with a $11,861 loss for the same quarter in 1978.

For the quarter, the Chevy Chase, Md. company's income dropped to $649,000 compared to $2.5 million for the same quarter in 1978.

UNC Resources Inc. announced a 92 percent earnings decrease for the second fiscal quarter, earning $765,000 (7 cents) compared with $9.6 million (88 cents) for the same quarter last year.

A year earlier, the company reported 17.1 million ($1.65) in profits for the six months. In the same period this year, UNC Resources reported profits of $6.9 million (64 cents).