April 3 (Reuters) - British advertising company WPP Plc is looking into accusations of "improper personal behavior" by chief executive Martin Sorrell, the Wall Street Journal reported on Tuesday.
The board of the world's biggest advertising company is also looking into whether Sorrell misused company assets, the Journal said, citing unnamed sources.
WPP's board has hired a law firm to investigate some of the issues, the newspaper reported.
The WSJ report gave no further details on the accusations.
WPP did not immediately reply to emails and calls for comment.
One of Britain's best-known business leaders, Sorrell built advertising group WPP from a two-man operation in a London office in 1985 to one that now dominates the industry with around 134,000 staff in more than 100 countries.
Reporting by Shalini Nagarajan in Bengaluru, Editing by Rosalba O'Brien