Ordinarily, our pages would be filled with the latest news on government contracting, commercial real estate, technology, banking and the business of law, but this week we take time out to focus on the region’s very biggest — the companies, law firms, nonprofits and other organizations that power our local economy.¶ It doesn’t take long to go through the list to realize just how diverse the greater Washington business establishment has become, and how connected we still are to the fortunes of the federal government.

Perhaps the best place to see the breadth of our economy is on our private company list. At the top is Mars, the candy giant, followed by one of the nation’s largest auto insurers — Geico, hotel giant Hilton Worldwide, the sprawling staffing firm Allegis, Clark Construction and then a string of government contractors.

Indeed, government contracting remains our largest industry. The three largest public companies on our list are defense or federal contractors.

Our business community has remained relatively stable, despite the choppy economic recovery. Nine of the 10 largest public companies on our 2011 list made the top 10 this year, the exception being Bethesda’s Coventry Health Care, which is merging with Hartford, Conn.-based Aetna. (Science Applications International Corp. is likely to fall out of the top group in 2013 after it splits itself in two.)

Fannie Mae and Freddie Mac continue to dominate the mortgage finance landscape, even as they remain wards of the federal government as Congress weighs what to do with the government-sponsored enterprises. They are joined this year by an old-line local firm, Walker & Dunlop, which also specializes in financing multifamily projects.

Other newcomers this year include Chantilly-based Engility, a government services provider spun off and taken public by L-3 Communications. It debuted at No. 24 on the public list. Also on the list is Carlyle Group, a veteran of the Post 200. But this year the once-private concern is now a public company after completing an initial public offering of stock in May.

Another newcomer is Siemens, the German conglomerate that established its headquarters in Washington. EagleBank, the fast-growing community bank based in Bethesda, cracked the list for biggest banks, while Venable edged Patton Boggs off the law firm list (Patton retains its place in the Post 200 as the region’s largest lobby firm.)

The Post 200 is an evolving document, a snapshot of local business. We are continually tinkering with our formula to get the best cross-section of companies. Let us know what you think. E-mail us at capbiznews@

— Dan Beyers