The Chicago area boasts three companies in the top 50 of the Fortune 500, in the face of group mergers and closings that have seen the departures of once-venerable names such as Ameritech, Amoco, Quaker Oats and Standard Oil.

This year's Fortune 500 list, based on the nation's largest companies by returns, includes 33 Chicago and Illinois-based companies.

Tops on the list are airplane-maker Boeing at No. 27 with more than $66 billion in sales; drugstore giant Walgreen at No. 40 with $53.7 billion in sales, and Sears Holdings, the Hoffman Estates-based dealer, at No. 45 with more than $50 billion in sales.

Others on the Fortune 100 list from Illinois include Caterpiller, in Peoria, at No. 50; State Farm Insurance of Bloomington at No. 32, and Deere, based in Moline, at No. 98.

Chicago's fringes are home to Allstate, the Northbrook insurer, at No. 64; Motorola, the Schaumburg-cell-phone producer ranked No. 65, and Abbott Laboratories, the North Chicago pharmaceuticals company at No. 96.

Below the 100 ranking are McDonald's at No. 106; United Airlines parent UAL at No. 124; Sara Lee at No. 125 and Exelon at No. 150.

Trailing were 20 other companies including Smurfit-Stone Container, CDW, W.W. Grainger and Wm. Wrigley Jr. Co.

Local grocery-store chains Jewel-Osco and Dominick's are owned by Fortune 500 companies headquartered elsewhere. Dominick's owner, Safeway, of Pleasanton, Calif., came in at No. 55, while Jewel parent Supervalu of Eden Prairie, Minn., ranked No. 62.