Despite a strong PR performance, Interpublic today reported a 3.2 percent slide in Q3 revenues to $1.7B and a 24.1 percent drop in operating income to $131.4M.

CEO Michael Roth said the “year has proven to be more challenging on the revenue front than anticipated.” A key hurdle was “incremental client caution being felt across our industry,” according to Roth. U.S. revenues fell 5.5 percent to $940.5M, while international was flat at $729.9M.

Roth added “we continue to manage the business effectively and will deliver increased full-year profitability relative to 2011.”

Interpublic’s PR units turned in a “terrific” performance and see more opportunities ahead (e.g., content-creation, social media), Harris Diamond, chief of the constituency management group, told O’Dwyer’s.

He said PR combined for a 5.9 percent “organic” growth rate during the 3Q period, which compares to an overall 0.9 percent decline at the corporate level. Diamond said some of that growth was related to the London Olympics.

Weber Shandwick, GolinHarris, DeVries PR, Rogers & Cowan and PMK*BNC spearhead IPG’s PR unit.

For the nine-month period, IPG showed a one percent decline in revenues to $4.9B and an 11.1 percent dip in operating income to $268.4.