A surge in organic growth, particularly in the U.S., boosted quarterly and full year revenue results for Interpublic. The ad/PR holding company today reported that organic revenue was up 5.2 percent during 2015's fourth quarter and 6.1 percent for the entire year, with IPG reporting nearly $2.2 billion in revenue for Q4, accounting for total yearly revenue of $7.6 billion, up from 2014's $7.5 billion.

Organic revenue growth in the U.S. was cited as a major source of activity, where organic revenue ticked up 6.2 percent in the quarter, versus an increase of 4.1 percent internationally during the same period. Organic revenue jumped 6.8 percent in the U.S. for the full year, compared to 5.3 percent internationally.

Michael RothMichael Roth

Net income was $283 million for 2015's fourth quarter, down from $331 million during the same period in 2014, and net income for the full year was $480 million, revealing a similar decline from 2014's $505 million.

Operating income was $456 million during Q4, compared to $433 million during 2014's fourth quarter. Operating income for the entire year was almost $872 million, compared to $788 million in 2014.

In an earnings statement, IPG Chairman and CEO Michael Roth said that, "from every perspective, 2015 was a very successful year, with notable accomplishments in the marketplace and strong financial results. Across the group, the quality of our people and our offerings is at its highest level in well over a decade. The key drivers of our industry-leading organic revenue performance have been talent acquisition and development, particularly in creative and strategic roles, our 'open architecture' model of integrating services, as well as the deep digital expertise we have embedded into our agencies. Our commitment to developing new skills, products and technology-enabled capabilities has allowed us to stay highly relevant in a very dynamic industry."

Roth also said IPG is now targeting organic growth between three and four percent for the year.

Weber Shandwick, the PR unit owned by Interpublic's Constituency Management Group, has also exhibited a particularly strong performance during both the quarter and the year, buoyed especially by that agency’s digital and content offerings, according to Weber Shandwick CEO Andy Polansky.

"Weber Shandwick in 2015 had double-digit organic growth on top of double-digit organic growth the previous year; it had organic growth in the high-single digits in the fourth quarter. We’re seeing this growth across geographies and practices. Our regions around the world continue to outperform, with more than 20 markets witnessing double-digit growth in 2015, and strong practice performance led by Consumer, Corporate and Healthcare," Polansky told O'Dwyer's. "Weber Shandwick’s digital and content capabilities, in particular, continue to be a huge drivers, accounting for 30 percent of our growth in 2015. We continue to see clients look increasingly to us for innovative and integrated marketing solutions as they navigate the complex media environment.”