Sorrell in advanced talks to buy ad group MightyHive

LONDON, Dec 3 (Reuters) - Martin Sorrell's new company S4 Capital said on Monday it was in advanced talks to buy MightyHive, a San Francisco-based programmatic advertising group that partners with major brands.

Sorrell, the founder of WPP, launched S4 Capital earlier this year after he left the world's biggest advertising group over a complaint of personal misconduct, which he denied.

In July he pipped WPP in the race to buy Dutch digital agency MediaMonks for around 300 million euros. He plans to build a new business offering content, digital analytics and technology to help clients reach customers in a rapidly changing media environment.

MightyHive uses algorithms to buy and sell advertising space online in real time.

(Reporting by Kate Holton; Editing by Kirsten Donovan)