
The tranche of 122,536 shares was sold yesterday (8 March), during which WPP's share price ranged between 628p and 647p.
It equates to just 0.7% of the total of 17 million WPP shares Sorrell and his family interests own or have rights to; the amount accounts for 1.36% of the company.
Sorrell has just become entitled to receive 722,678 shares awarded to him by two separate executive bonus schemes.
He has deferred receipt of 562,245 shares awarded to him under one scheme, the company's Leadership Equity Acquisition Plan, in 2005. He is entitled to exercise his option to receive these shares at any time until 30 November 2012.
He also became entitled to receive 160,433 shares awarded in 2008 in the company's Executive Share Awards scheme. A WPP spokesman said it was likely Sorrell sold the shares yesterday to meet taxes in connection with this award.
Two other executives, finance director Paul Richardson and strategy director Mark Read, also received shares this week under the two schemes, and sold a number of shares yesterday.