SAS, the world’s largest privately held software firm, ranks 20th in the new Fortune Magazine list of the for which to work.

SAS was one of only 15 firms among the 100 that cracked Fortune’s “Best Perks” list. The 15 companies pay 100 percent of health insurance premiums for their employees.

SAS rose nine places from 29th in Fortune’s 2008 list.

After dropping to 48th in 2007 from 30th in 2006, the Jim Goodnight-owned firm surged for the second straight year in rankings that are based on a variety of criteria. Fortune’s criteria include benefits, salaries, job growth, turnover and roles for women and minorities

Several other firms with a strong presence in the Research Triangle area and North Carolina also made the list.

NetApp, which operates a campus in RTP, came in first on the Fortune list.

Cisco is sixth.

Novo Nordisk, a life-science firm that operates a large plant in Clayton, placed fifth

Consulting engineering firm Kimley-Horn & Associates, which is based in Cary, ranked 35th.

Law firm Alston & Bird ranked 36th. It has offices in Raleigh and Charlotte.

Google ranked fourth. It operates a data center in Lenoir.

Microsoft, which maintains a large operation in Charlotte, ranked 38th.

Fortune noted that most of the companies on the list are still hiring despite the global recession.

NetApp grew its work force 12 percent in 2008, SAS 5 percent and Cisco 7 percent.

Other work force expansion percentages, according to the magazine: Google 40; Cisco 6; Alston & Bird 7; Microsoft 15; Novo Nordisk 11.

Kimley-Horn reported an 8 percent drop in its headcount to just under 2,200.

Company rankings were based on a survey of 81,000 employees at 353 companies. The survey, which included 57 questions, was prepared by the Great Place to Work Institute.