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

The annual census of Washington's Top 100 companies shows the local business climate in the past year has been a lot like the weather:

The winter of recession was chilly, but not nearly so bad as feared.

The spring recovery seemed like it would never get started, then suddenly things sprouted like they did last week, it was summer again and Washington business was back to normal.

The anxieties that dominated the 1981 annual reports of Washington corporations have been replaced by a consensus summarized by W. Jarvis Moody, chairman of American Security Corp.: "We look for an improved economic environment in 1983, but expect the pace of recovery from the recession of 1981-82 to be slower than past recoveries."

Washington's biggest businesses suffered the most from the recession, while many smaller companies kept right on growing.

The big loser of the year was the biggest outfit in town, the $73 billion Federal National Mortgage Association, which lost a staggering $104.9 million before turning around in the first quarter of 1983.

A dozen other companies ended the year in the red: UNC Resources dropped $14 million in the process of a major corporate restructuring. Perpetual-American Savings & Loan lost $11.4 million but survived the interest rate peak with the healthiest reserves of any local savings institution. B. F. Saul Real Estate Investment Trust lost $4.4 million, but like Fannie Mae, turned around in early 1983.

Martin Marietta Corp., the largest local industrial firm, very nearly vanished from the Top 100 list when it became the target of 1982's most traumatic takeover fight. Allied Corp. rescued Marietta from the clutches of Mary Cunningham, William Agee and Bendix Corp., but not before Marietta's earnings plunged from $200 million to $91 million.

Marietta's Montgomery County neighbor, Fairchild Industries Inc., suffered a similar decline in profits--from $64.3 million to $35.3 million--and Geico Corp. earnings fell from $83.3 million to $48.8 million.

Geico Chairman John J. Byrne earned the annual report candor award for telling his shareholders up front, "We did not attract as many new customers as we should have. We spent more money than we should have. We did not move as agressively as we should have . . ."

In contrast, Flow General Corp. responded to stockholder lawsuits, a federal indictment and a 33 percent drop in earnings, from $7.2 million to $4.8 million, by issuing the slickest, thickest annual report of any Washington business with a message from Chairman Joseph E. Hall that said:

"These results were disappointing . . . and while I do not minimize the significance of the decline in earnings, I believe it is important to maintain an accurate perspective of 1982." Noting that "these results were achieved during one of the most difficult economic periods in recent history," Hall assured shareholders of "our ability to emerge from this period in a strong financial position."

Within weeks after that message, Hall was fired, and Flow announced it was trying to sell two of its most promising divisions--its Interferon cancer research project and Worthington Diagnostic Systems, which it acquired less than two years ago.

Flow survived the year with the most serious internal wounds of any Washington business, though management missteps and lawsuits gave American Management Systems a $1 million loss for the year.

Such difficulties were rare among the high-technology companies that are making the Washington area one of the nation's most innovative industrial incubators. Planning Research Corp. posted one of the strongest turnarounds, flipping from a $489,000 loss to a $14.5 million profit.

Cerberonics Inc., the defense contractor that takes its name from Cerberus, the mythical three-headed dog that guarded the gates of Hades, gave its stockholders a heavenly 114 percent increase in earnings and a 50 percent increase in revenues.

CACI Inc., which mixes a little marketing research into its military contracting, grew from a $58 million operation to $95 million and boosted its profits by 91 percent to $4.4 million.

Other outfits that defied the recession included C3 Inc., profits up 68 percent; Atlantic Research, up 49 percent; Advanced Technologies, up 47 percent; BDM Corp. and Computer Entry Systems, up 46 percent, and General Physics, up 41 percent.

It was not only the technology companies that made such strong gains. Acquisitions pushed Manor Care revenues from $91 million to $261 million in one year, and earnings jumped 48 percent to $10.2 million. The Washington Post Co. profits soared 60 percent from $32.7 million to $52.7 million. Giant Food rebounded from a profit-pruning food war with a 122 percent increase and a $37.2 million bottom line.

In sheer revenue growth, no local company could match Marriott Corp. which boosted annual volume $500 million to $2.5 billion. Already the most profitable firm in town, MCI Communications could show even greater percentage and dollar gains in revenue when its annual earnings come out next week. Unless they run into unexpected difficulties, MCI and Marriott will soon be battling it out for the title of Washington's biggest business.