Presidential Airways Inc., a Washington-based passenger airline, said its third-quarter loss narrowed to $4.8 million from $5.8 million a year ago as revenue fell to $16.6 million from $24.7 million.

The company -- which operates Continental Jet Express service from Dulles Airport to 11 cities and Continental Express commuter service from Dulles to 11 destinations, both under a marketing arrangement with Continental Airlines -- said it lost $14.2 million in the first nine months of the year, compared to a $19.2 million loss in the first nine months of 1986. Revenue for the nine months decreased slightly, to $52.3 million from $54 million a year ago.

Penril Corp., a Rockville electronics and electrical equipment company, said it earned $259,000 (11 cents a share) in its first quarter that ended Oct. 31, compared with a $171,000 loss in the same quarter a year ago.

Penril said revenue decreased 36 percent in the quarter, to $9.1 million from $14.3 million, as the company completed a restructuring program.

PHP Healthcare Corp. of Alexandria said its second-quarter profit dropped 19 percent, to $149,138 (4 cents) from $184,311 (6 cents) a year ago, when the company's results included a $90,200 extraordinary tax credit.

PHP's revenue in the quarter, which ended Oct. 31, rose nearly 60 percent, to $11.3 million from $7.1 million.

For the first half of the year, PHP's profit rose 6 percent to $367,647 (10 cents) from $346,858 (12 cents) a year ago. Revenue for the half went up 69 percent, to $21.7 million from $12.8 million.

Per-share earnings figures for the quarter and the half were affected by the recent issuance of 750,000 shares of common stock, the company said.

Sporting Life Inc., an Alexandria mail-order apparel retailer, has restated its first-quarter earnings after its corporate auditors decided to allow a tax loss benefit of $165,000. That reduced the company's previously announced first-quarter loss to $171,884.

The company said its revenue figure for the quarter remained at $3.3 million. A year ago, Sporting Life earned $120,151 (12 cents) on $3.3 million sales in the first quarter.