Chime Communications, the owner of Good Relations and Harvard PR, is buying international motorsport marketing firm JMI for up to £43.7m.
JMI (short for Just Marketing, Inc) was founded in 1995 and employs around 130 people in the US, UK and Hong Kong. It is focused mainly on Formula 1, NASCAR and IndyCar.
Chime, in which WPP is a major shareholder, also announced plans to raise approximately £25.6m by issuing new shares.
JMI will become part of Chime’s sports marketing division, CSM Sport & Entertainment, which is chaired by Lord Sebastian Coe.
Coe said: "This is the most sizeable acquisition CSM Sport & Entertainment has made to date and signals our strategic entry into the exciting world of motorsports and the important US market."