Editor's note: A previous version did not include Chattanooga's biggest trucking company, U.S. Xpress Enterprises.
The biggest companies headquartered in the Chattanooga area with annual revenues last year near or more than $1 billion included:
1. BlueCross BlueShield of Tennessee, Chattanooga-based health insurer, $15.2 billion
2. Unum, the Chattanooga-based employee benefits company, $11.6 billion
3. Tennessee Valley Authority, wholesale electric utility, $11.2 billion
4. Mohawk Industries, the Calhoun, Georgia-based floorcovering manufacturer, $10 billion
5. Shaw Industries, Dalton, Georgia-based carpet manufacturer, $6 billion
6. Life Care Centers of America, Cleveland, Tennessee-based nursing home chain, $2.44 billion
7. U.S. Xpress Enterprises, Chattanooga-based trucking company, $1.7 billion
8. McKee Foods Corp., Collegedale-based snack cake bakery, $1.4 billion
9. EMJ Corp, Chattanooga-based construction firm, $960.2 million
10. Astec Industries, Chattanooga-based heavy equipment firm, $990.6 million
Sources: Company annual reports, D&B Hoover's estimates, Forbes list of largest privately-owned companies.