The executive recruiting industry is a $13 billion offshoot of the employment agency industry. Like its parent industry, executive recruiting is comprised of large and small firms providing permanent and temporary employment placement to client businesses. Executive recruiting firms place junior, mid-level and senior executives earning a minimum of $50,000 annually, and some firms restrict themselves to jobs paying over $100,000 per year. Currently there are over 4,000 executive search firms in North America; 1,600 of these work on a retainer basis. The three largest retained executive recruiting firms in the U.S. are Korn/Ferry International, Heidrick & Struggles International Inc., and Russell Reynolds. Together, they account for over $1.5 billion in annual revenues.