Publicis Groupe's Q3 organic revenues dropped 2.7 percent as the French ad/PR combine turned in a worse than anticipated performance.

CEO Arthur Sadoun doesn't expect much relief ahead as he lowered full-year revenue guidance to a 2.5 percent decline.

He blamed Q3's downbeat results on technology transformation costs, "cuts from a handful of clients on traditional advertising mainly in the US" and "softer than expected" results in media operations.

He said Publicis is streamling and simplifying its organization to seamlessly connect creativity, media, data and technology.

The firm is willing to accept short-term financial pain to be better prepared for the future, according to Sadoun.

"We have taken the tough but necessary decisions needed to tackle the industry challenges we are facing head- on," said Sadoun in a statment. "We are without a doubt at the hardest part yet of our journey and as is the case with any major structural change, things always get worse before they get better."