Martin Sorrell

Since then, WPP became one of the world's leading communications services and advertising companies valued by the UK stockmarket at £7.5 billion.

With billings of $15 billion and revenues of $3.5 billion, WPP's 70 operating companies provide national, multi-national and global clients with advertising, media investment management, information and consultancy, public relations and public affairs, branding and identity, healthcare and specialist communications services. Sorrell's firm employs 65,000 people in 950 offices in 92 countries.

Before founding WPP, Martin Sorrell helped run famed UK advertising agency Saatchi & Saatchi from 1977 until 1984.

He is a graduate of Cambridge University and has an MBA from Harvard University.

He was Knighted in the Millennium New Year Honours list.

Sorrell was in 2005 forced to sell £9m of shares in WPP to pay a tax bill, due to an Inland Revenue clampdown on executive tax avoidance arrangements.

He also agreed to change a contract with the company which had been much criticized by institutional shareholders in WPP as being unfairly written in Sorrell's favor. Under the previous agreement if Sorrell was terminated it would have led to a very large payout. The new agreement instead provides him with one year's pay. Shareholders have criticized many aspects of corporate governance at WPP.

Sir Martin owns a substantial stake in the company he founded through a series of pay awards and his own purchases of shares. Until recently he had never before sold shares in the company.