Revenue grew 19.2 per cent to €1.034bn (£750m, $1.16bn), with operating income up 22.4 per cent to €128m (£93.4m, $143.9m). Operating margin increased from 13 per cent to 13.5 per cent.
Havas CEO Yannick Bolloré said: "This strong first-half performance gives us every confidence that our annual targets will be met."
Marian Salzman, CEO of Havas PR in North America and chairperson of the Havas PR global collective, was upbeat about the performance of the PR business, which includes Maitland, Cake and Havas PR. No figures are available, but Havas’ PR performance was "consistent with or better than the numbers reported by Havas", she said.
"Our US PR agencies are doing well; Havas PR... and Formula are all doing well.
"In Australia, the Red Agency and One Green Bean continue to thrive, and we’ve had the One Green Bean expansion into the UK this year.
"Cake continues to do quite well, both in the US and especially in the UK."
The French holding company made five main acquisitions in the period, including London-based health PR agency Just:: Health Communications.
Asked if more PR acquisitions are planned, Salzman said: "If there’s a chance to be strategic and acquire things, we will do that."
Organic expansion is also on the cards. Salzman highlighted the opening of a Havas PR office in Phoenix, Arizona, which is performing "incredibly well".
Overall, Havas saw strongest organic growth in North America during the half-year (+9.2 per cent). Organic growth in Europe was 4.8 per cent, with the UK at +5.1 per cent, France at +2.4 per cent and the rest of the continent growing at seven per cent.
Organic growth in APAC & Africa and Latin America was 5.4 per cent and 3.2 per cent respectively.