The company said its pro-forma revenue would have been £135.9m had its two acquisitions, MediaMonks and Mightyhive, been part of S4 for the duration of the year.

Gross profit was £37.2m and pro-forma gross profit £105.2m, up 49% on 2017.

S4 Capital acquired Dutch digital agency MediaMonks in July 2018 and programmatic advertising firm Mightyhive in December.

The company now consists of around 1,200 staff in 16 countries.

Sorrell, executive chairman of S4 Capital, said: "It is clear that the company’s purely digital model based on first party data fuelling digital content and programmatic is resonating with clients. Our tag line ‘faster, better, cheaper’ and unitary, one P&L structure also appeal strongly."

Sorrell added that the company’s focus will be to "broaden and deepen" its relationships with existing and new clients and its geographical coverage, and to "attract additional data, content and media talent and resources through direct recruitment, acquisition and/or merger".