(Bloomberg) -- WPP Plc reported a slight improvement in sales as managers of the world’s largest advertising group face shareholders for the first time since the dramatic departure of its founder, Martin Sorrell.

WPP said like-for-like revenue less pass-through costs rose marginally in the first four months as strong April growth in Western Continental Europe, Latin America and Central and Eastern Europe offset a decline in North America. That was an improvement compared with a first-quarter decline of 0.1 percent.

Executive Chairman Roberto Quarta has come under fire following the exit of former Chief Executive Officer Sorrell, with calls for WPP to release the details of the investigation into personal misconduct and misuse of company assets that led to Sorrell’s ouster in April. Multiple reports this week said WPP investigated allegations that Sorrell used company money to pay for a prostitute, allegations he denies.

WPP shares are down 24 percent over the past year, as major clients like Procter & Gamble Co. have cut marketing spending and investors fret about the rising influence of Facebook Inc. and Alphabet Inc.’s Google. WPP also faces challenges from consultants such as Deloitte LLP and Accenture Plc, which are increasingly competing for digital marketing projects.

Analysts have speculated that WPP, a sprawling network of more than 400 agencies, could be broken up. A top priority for interim co-chief operating officers Mark Read and Andrew Scott is to retain major clients like Ford Motor Co., while the company searches for a new CEO.

Neither Sorrell, who isn’t present at Wednesday’s shareholder meeting, nor the company have publicly discussed details of the departure, citing a confidentiality agreement. WPP has maintained that the funds in question weren’t material. Sorrell has denied any wrongdoing.

To contact the reporters on this story: Joe Mayes in London at jmayes9@bloomberg.net;Thomas Seal in London at tseal@bloomberg.net

To contact the editors responsible for this story: Rebecca Penty at rpenty@bloomberg.net, Kim Robert McLaughlin

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