The unit includes Weber Shandwick, GolinHarris, DeVries, Current Lifestyle Marketing and Axis.
Polansky was speaking after Interpublic revealed its Constituency Management Group (CMG) reported a 5.7 per cent year-on-year organic revenue increase in Q1 to $321.8m (£191.4). CMG houses most of its PR agencies but also non-PR shops such as event production specialist Jack Morton and sports marketing agency Octagon.
Spong, recently rebranded from Carmichael Lynch Spong, operates outside of CMG.
Polansky added that Weber performed strongly in North America, Asia, Brazil, and the UK, and it is seeing growth opportunities through its Mediaco content creation and distribution unit.
The firm’s recent wins include Qualcomm and Transamerica, he said, adding that he is optimistic about the rest of 2014.
"We’ve invested heavily in scaling our capabilities in digital and social; we continue to add expertise across our practice areas, and those investments are fueling organic growth across our client portfolio," Polansky explained.
Overall, IPG’s revenue grew 6.6 per cent organically to $1.6bn (£951m) in the period, compared with the previous year. The US achieved a 4.8 per cent organic increase in revenue during the first quarter, while internationally the holding company posted organic growth of 9.1 per cent.
The holding company reported an operating loss of $12m (£7.1) in the quarter, compared with a loss of $42m (£25m) in the same period of last year.
Organic growth represents change in revenue without measuring the impact of acquisitions and disposals.