The historic sex charges date back two decades and involve women and girls as young as 15. The 71-year-old was convicted on eight counts of assault in Southwark Crown Court.
He was cleared on two other charges and the jury failed to reach a verdict on one other sex charge. The PR guru had pleaded his innocence, declaring the prosecution "a nightmare" and branding the victims as "fantastists".
After the Jimmy Saville scandal detectives launched a string of investigations into household names as part of the Yewtree Operation. Various women came forward separately to claim they were abused between 1966 and 1984.
In response the publicist said their allegations were "utterly revolting, utterly untrue, disgusting lies". He did admit to "slap and tickle and kisses and cuddles" in his office and affairs with two female employees.
However, he said those relationships "developed naturally" and were "morally wrong" because he was married - as opposed to criminal.
But the court heard from prosecution lawyers that he used promises of fame and meetings with celebrities "to bully and manipulate" young people into sexual acts.
In a career spanning more than 40 years, the controversial PR has represented clients such as Rebecca Loos, Mohamed Al-Fayed, Frank Sinatra and Marvin Gaye.
He will be sentenced on Friday.