The marketing services company, which also owns media agencies PHD and OMD, says revenue in the first three months of the year hit $2.9bn (£1.9bn), up from $2.7bn (£1.7bn) in the first quarter of 2009.
Revenue gains helped drive pre-tax profit up to $266.9m (£173m), from $261m (£169m) a year earlier.
Agency group revenues have been boosted by an increase in advertising spending as global economies come out of recession.
Rival Havas, owner of Euro RSCG and Arena BLM, recently reported a 1.5% revenue increase for the first quarter.
The results come in the week that the IPA/BDO Bellwether reported the first upward revision of marketing budgets since 2007.
The report said around 21% of companies reported a rise in their budgets, while only 16% noted reductions in the first quarter.