Federal Realty Investment Trust, a Bethesda-based company that acquires and renovates shopping centers, said its operating income rose in the second quarter and first half, but net earnings fell from a year ago, when profits were inflated by the sale of a shopping center.

The company earned $2.48 million (14 cents a share) in the second quarter, down 68 percent from a profit of $7.76 million (55 cents) in the year-ago second quarter. Revenue rose 13 percent in the quarter, to $22.7 million from $20.1 million.

For the first half, the company earned $4.1 million (24 cents), down 55 percent from 1989 first-half earnings of $9.15 million (66 cents). Revenue climbed 9 percent in the half, to $44.3 million from $40.8 million.

The year-ago results reflected the sale of the Akers Shopping Center in Gastonia, N.C., the company said. Income from operations rose 15 percent in the second quarter and 28 percent in the first half due to intensified leasing efforts, improved performance from recently renovated shopping centers and growth in its real estate portfolio, it said.

Washington Real Estate Investment Trust, which owns 28 commercial real estate properties around the area, said increasing occupancy in its buildings helped push its profit up 16 percent in the second quarter and 19 percent in the first half.

The trust reported a profit of $4.1 million (26 cents) in the second quarter, compared with $3.5 million (24 cents) in the second quarter of 1989. Revenue rose 10 percent during the quarter, to $7.6 million from $6.9 million.

It earned $7.9 million (51 cents) in the first half, compared with a 1989 first-half profit of $6.6 million (46 cents). Revenue rose 8 percent in the first half, to $14.7 million from $13.7 million.

The company said it achieved a 94 percent occupancy rate in the second quarter among a portfolio of properties that includes office and warehouse-industrial buildings, shopping centers and apartment buildings.