The plan, which gives senior executives who have bought shares the chance to get up to five times as many free shares back if the firm outperforms its major rivals over the next five years, was approved by 83.06% of stockholders.

The Association of British Insurers had urged its members to vote against the scheme, but other groups called on shareholders to back it.

According to press reports WPP CEO Martin Sorrell could make up to £60m through the plan.

The marketing services group, which owns research agencies TNS and Millward Brown among others, issued a trading update at the AGM in which it said its insight, information and consulting operations had been “most affected” by the recession during the first four months of 2009.

During the period the group’s revenues were down 6.7%, excluding the impacts of acquisitions and currency fluctuations. In line with this, WPP said it had reduced the number of staff worldwide by almost 4,300, or 3.7%. “Over half of the people who left, did so on a voluntary basis,” the group said.

In other news today, WPP has swapped assets with Brazilian market and media research group Ibope. The Brazilian firm has acquired 100% of Puerto Rican media research agency Mediafax from WPP in return for WPP upping its minority shareholding in Ibope’s subsidiaries Ibope Pesquisa de Midia, Ibope Latinoamerica and IMI.co. WPP already owns a 42.15% stake in Ibope.