NEW YORK—Omnicom Group, which owns numerous PR firms including FleishmanHillard, Ketchum and Porter Novelli, has reported PR revenue of $1.36bn for 2015, a 1.4% organic decrease on PR revenues in 2014.

The decline comes after disappointing growth for Omnicom's PR firms in the fourth quarter of 2015, when revenues dropped 6.9% on an organic basis to $340m. In its previous 2014 fiscal year, Omnicom's PR firms grew topline by 4.1%, after a strong 4Q.

On a reported basis, PR revenues were down 7.7% in 4Q 2015, and -2.3% for the year.

Omnicom's PR unit was the worst performer among its four divisions during 4Q 2015, lagging advertising (+12.6%), CRM (-1.5%) and specialty communications (-5.9%).

Overall, the group posted a 1.2% drop in worldwide revenue for 2015, to $15.13bn.

As noted by the Holmes Report's M&A analysis, Omnicom was relatively inactive in terms of acquiring PR firms in 2015. Brazilian PR firm CDN came onboard as part of the Grupo ABC deal, while a controlling interest in public affairs shop Mercury New Jersey was also acquired.