Anderson, who has been with the company for more than seven years and previously held the role of vice-president, has been promoted to managing director.
Former head of digital Hayes has been made chief innovation officer.
Bhatt, former head of UK theatrical publicity at Studiocanal, joins the board in a newly created position, president of film and television. He will be responsible for the consultancy’s film and television clients including production publicity, festival activity and BAFTA Awards promotion.
Prevezer, founder of The Communications Agency, has been brought in as non-executive chairman to oversee strategy and business development.
The quartet join CEO Lawrence Atkinson, COO John Stannard and president Dana Archer on the company's board.