Potomac Electric Power Co. reported a $7 million improvement in quarterly profits even though revenue from electricity sales slipped by about the same amount.

The Washington utility's quarterly earnings grew to $72.5 million ($1.45 a share) from $65.5 million ($1.31), while revenue fell to $398 million from $405.5 million.

For the first nine months, Pepco's net grew to $139 million ($2.69) from $113.1 million ($2.17) and revenue increased to $922 million from $914.5 million. Pepco said electricity sales for the year so far are up 4.7 percent over the same period a year ago.

The Richmond, Fredericksburg and Potomac Railroad Company said its third-quarter profits grew to $4.8 million ($13.34) from $3.1 million ($8.57), while revenue increased to $14.2 million from $13.5 million. President John Newbauer said the railroad carried about 10 percent more freight during the quarter than last year and earnings were boosted about 78 cents a share by profits on sales of land.

For the first nine months, the RF&P earned $13.2 million ($36.79 a share), up 19 percent from the $11.1 million ($30.82) earned in the same period a year ago. Railroad operating revenue was up 6 percent to $43.7 million from $41.2 million and freight tonnage was up 6 percent.

Avemco Corp. of Frederick, Md., reported its third-quarter net grew to $1.1 million (36 cents) from $807,000 (29 cents), and earnings for the nine months jumped to $4.2 million ($1.37) from $3.1 million ($1.19).