Diversified consulting firm Oliver Wyman Group is led by its Oliver Wyman unit, a management consulting specialist that operates from more than 40 cities in about 20 countries worldwide. Oliver Wyman, which draws clients from a variety of industries, offers advice on business transformation, leadership, marketing and sales, operations and technology, risk management, and strategy. Other Oliver Wyman Group units include Lippincott (branding and identity) and NERA Economic Consulting. Oliver Wyman Group is a unit of insurance giant Marsh & McLennan, whose subsidiaries also include Mercer, a human resources and benefits consulting firm.