Several errors occurred in last week's compilation of Washington's Top 100 companies. Assets of Potomac Electric Power Co. as of Dec. 31, 1982, totaled $2.7 million. Pepco ranks third in assets, behind C&P Telephone and Martin Marietta Corp. Assets of BDM Corp. as of Dec. 31, 1982, totaled $53.7 million, 35th among Washington nonfinancial companies. BDM now has 2,450 employes and about 85 percent of its business is defense-related. The firm's profits increased 46 percent last year; revenue was up 34 percent. Assets of Manor Care Inc. as of the end of its fiscal year on May 31, 1982, totaled $426.5 million, 14th in the area. Now traded on the New York Stock Exchange, the Silver Spring health care firm has 1,700 employes in the Washington area and 16,000 worldwide. It was incorrectly reported that Syscon Corp. was acquired by Continentel Telcom. Continental Telcom acquired STSC Corp. With sales of $71.4 million, Syscon ranks 33rd among Washington-area nonfinancial corporations. Evaluation Research Corp. was omitted from the listings; the firm ranks 54th in revenues at $17.3 million. Profiles of Syscon and Evaluation Research appear on this page. The Norfolk Southern Railroad was removed from the Washington companies list after the newly merged railroad said it was consolidating headquarters operations in Norfolk. With revenues of $3.3 billion, and assets of $6.8 billion, Norfolk Southern ranks second among Virginia corporations. Earnings last year totaled $411.4 million ($6.57 a share). PHH Group and Allegheny Beverage Corp. were not listed among the 10 largest Maryland corporations based outside the Washington area, though both are larger than Easco Corp., the smallest industrial firm listed. PHH of Hunt Valley, a vehicle management and cost control firm, earned $29.6 million ($1.93 a share) on revenues of $471.7 million. Allegheny Beverage, a Pepsi-Cola bottler and owner of The Macke Co. in Washington, earned $9.4 million ($2.30 a share) on revenues of $453.4 millio

USAir Group Inc. 1911 Jefferson Davis Hwy. Arlington, Va. 22202 REVENUE: $1.3 billion PROFITS: $59.1 million EARNINGS PER SHARE: $3.35 ASSETS: $1.1 billion DIVIDEND: 12 cents DESCRIPTION: USAir Group Inc. is the holding company for USAir, a regional airline serving markets mostly on the East Coast and in the Midwest, out of an operations base in Pittsburgh, with 119 airliners. It was known throughout most of its history as Allegheny Airlines. The company also operates Allegheny Commuter airlines, a confederation of several small regional commuter airlines. The commuter lines act as feeders to USAir flights. FOUNDED: 1937 TOP EXECUTIVE: Edward I. Colodny, chairman and president EMPLOYES: 11,000 DEVELOPMENTS: USAir continues to report strong results at a time when much of the rest of the airline industry is suffering. Operating revenues in 1982 were the airline's best ever, and its operating margin of 6.2 percent led all major airlines. Much of the past year was spent rebuilding service at the airline's Pittsburgh hub, which was seriously curtailed by the 1981 air controllers' strike. USAir says it is now exceeding previous departure levels from Pittsburgh; the airline accounts for 66 percent of the departures from Pittsburgh. USAir has carefully taken advantage of deregulation of the industry to expand conservatively to new markets, an expansion that increasingly belies its image as a regional carrier: service to Los Angeles and San Francisco from Pittsburgh was inaugurated recently. The company also has been gradually modernizing its fleet, and expects to retire the last of its early-generation Boeing 727s and BAC1-11 aircraft this year. ? Preston Trucking Co. Inc. 151 Easton Blvd. Preston, Md. 21655 REVENUE: $222.3 million PROFITS: $5.1 million EARNINGS PER SHARE: $1.64 ASSETS: $117.6 million DIVIDEND: 68 cents DESCRIPTION: Preston Trucking Co. Inc. is a common carrier principally of general commodity freight. Four of its five subsidiary companies were merged into Preston on Dec. 31, 1982. Preston operates more than 12,000 miles of authorized regular routes. The service extends on the East Cost between Norfolk and Boston and in the West between Milwaukee and St. Louis; rail links extend service to Florida and Texas. Preston's irregular routes for general commodity service extend nationwide. The Frontier Division handles refrigerated cargo and the remaining subsidiary, Pioneer Transportation, operates as a contract carrier. FOUNDED: 1932 TOP EXECUTIVE: A.T. Blades, chairman EMPLOYES: 4,026 DEVELOPMENTS: Heavy snow during the first two months of 1982, keener competition resulting from trucking deregulation and the recession were cited as key factors for Preston's drop in net income during 1982 to $5.1 million, down from $6.3 million in 1981. Revenues hit a record high in 1982 at $222 million, an increase from $197 million in 1981. First quarter income this year climbed 40 percent to $910,000 (29 cents) from $648,000 (21 cents), while revenue was up 17 percent to $60.9 million from $51.9 million. The opening of 10 new terminals, the growth of the Frontier Division (revenue up 81.5 percent to $27 million) and the success of a new intermodal service in the Southwest were cited as reasons for the revenue rise in the company's annual report. Preston's operating costs increased 15 percent in 1982 to $216 million due to the start-up costs of the new terminals and intense discounting that reduced potential revenues by $11 million. During 1982, Preston handled an average of 43,198 shipments a week. No single shipper out of more than 38,000 customers accounted for as 2 percent of revenues. Preston has started as Employe Stock Ownership Program and says, "one of our goals is to have each of our associates own stock in the company."