Adecco is the world's largest employment agency, serving some 100,000 clients from more than 5,500 offices worldwide. The company primarily provides temporary staffing services (more than 90% of sales), but also offers permanent employee placement, project assistance, outsourcing, and other human resources-related services. Besides its core industrial and office staffing services, Adecco maintains six professional lines: Engineering & Technical; Finance & Legal; Human Capital Solutions; Information Technology; Medical & Scientific; and Sales, Marketing & Events. Adecco traces its roots to 1957 and has a history of growing through mergers and acquisitions.