The largest public companies in the Greater Valley are a diverse breed, touching industries as varied as entertainment, aerospace, healthcare, advertising and biotechnology. With a current market value of $75 billion, The Walt Disney Co. is the largest, beating biotech giant Amgen Inc., which came in at No. 2, by more than $20 billion. The Burbank-based media and entertainment conglomerate saw its profit jump 21 percent to $4.8 billion on revenues of $40.9 billion for its last fiscal year. Only one business unit —the studio entertainment division — saw its revenue decline in fiscal 2011 as some feature films, including “Cars 2” and “Captain America” saw poor box-office results. Overall, revenue jumped 7.4 percent compared with a year earlier. Thousand Oaks-based Amgen was the second-largest public company in the area valued at $54 billion. The company is going through several transitions. It announced in the fall it was restructuring its research and development unit and shedding 380 employees. CEO Kevin Sharer is scheduled to step down in May when current President and Chief Operating Officer Robert Bradway will assume the company’s top post. Amgen has also jumped into the new world of biosimilar drugs, essentially generic versions of medicines made from live organisms. Northrop Grumman Corp., based in Falls Church, Va., still maintains a significant presence in Woodland Hills and Palmdale. The aerospace company has a market value of $15 billion and posted $2.1 billion last year, a slight rise from the previous year. It was No. 3 on the List. Health Net Inc., based in Woodland Hills, came in at No. 4 with a market value of $3 billion. The company saw revenue and profit decline last year. The managed healthcare provider saw revenue drop 13 percent to $11.9 billion and profit plummet 65 percent to $72 million. Rounding out the top 10 are Thousand Oaks-based Teledyne Technologies Inc. at $2.2 billion (5); Camarillo-based Semtech Corp. at $1.9 billion (6); Westlake Village-based ValueClick Inc. at $1.8 billion (7); Calabasas-based The Cheesecake Factory Inc. at $1.643 billion (8); Glendale-based DreamWorks Animation SKG Inc. at $1.641 billion (9); And Glendale-based PS Business Parks Inc. at $1.5 billion (10). Download the 2012 VALLEY’S LARGEST PUBLIC COMPANIES list (pdf)