FILE PHOTO: Sir Martin Sorrell, then chairman and CEO of advertising company WPP, attends a conference at the Cannes Lions Festival in Cannes, France, June 23, 2017. REUTERS/Eric Gaillard/File Photo

(Reuters) - More than a quarter of investors at WPP WPP.L have cast votes against a pay report to be discussed at Wednesday's annual general meeting, angered by benefits for former chief executive Martin Sorrell, according to Sky News reporter Mark Kleinman.

Most of the advertising giant’s shareholders vote ahead of time, so the company knows the results in advance, although they are not announced until the day. A spokesman for WPP could not be reached for comment.

The AGM has received much media attention because of the high-profile departure of Sorrell, the architect of WPP’s success and a titan of the industry over decades.

Up to 20 percent of shareholders oppose the re-election of WPP chairman Roberto Quarta to the board, Kleinman tweeted, without citing sources.

He said some investors were unhappy about remuneration arrangements that Sorrell will continue to enjoy after he has left.

Sorrell quit WPP after the board opened an investigation into an allegation of personal misconduct.

The company has not given any details and Sorrell has denied any wrongdoing. He told staff he had stepped down because the disruption of the investigation was putting too much pressure on the business.