Big global brands are well represented in the rankings, but 50 percent of the top 100 are under 7,000 employees, said LinkedIn.

"A strong consumer brand helps, but isn't essential," said the networking company. "Consumer powerhouses like Coca-Cola and Nike ranked highly, but so did leading professional services firms like McKinsey & Company and B2B companies like GE."

"Seventy percent of companies rank employer branding as one of their biggest priorities as they increasingly compete for top talent," said Steve Barham, senior director, LinkedIn Talent Solutions. "The ability to better understand how your company is perceived among key professional audiences empowers you to take steps to better engage the professionals you most want to hire."