LONDON—WPP's media research business Kantar Media has acquired a majority stake in UK media monitoring group Precise Media. 

The deal comes after reports last year that Precise owner Phoenix Equity Partners was preparing the company for a sale.

Phoenix bought Precise for £42m in 2006 from 3i. Terms of WPP's acquisition were undisclosed.

Founded in 1996 by Martin Knight and Chris Banner, Precise has grown to become a key player in the UK media monitoring scene, with a particularly strong client base across FTSE100 companies.

For the year ending 30 September 2013, Precise's revenues were £28.9m, with gross assets of £34.4m.

Precise now employs more than 430 people, including a number of analysts and software developers, reflecting growth in its SaaS products and integrated offline and online media monitoring platform.

In a statement, WPP said that "the acquisition strengthens the global expertise of Kantar Media in delivering media reputation tracking and impact analysis for PR campaigns across the board, bridging mainstream and social media with highly innovative technology."

"This acquisition continues WPP's strategy of developing its services in important markets and sectors and strengthening its capabilities in data investment management."

Worldwide, WPP's data investment management companies (including associates) collectively generate revenues of about US$5 billion and employ over 34,000 people.