Stocks in the parent company of McCann Erickson, Universal McCann, Draft FCB and Lowe closed at $8.26, down 9c.
In March this year, Interpublic announced it was to axe more than half of Lowe Worldwide's offices in what it claimed was an attempt to improve its profitability, following four years of financial difficulties and accounting irregularities.
Since Michael Roth was appointed chief officer in 2004 the company has seen its share price drop by 37%.
In May, the group reported a first-quarter loss of $182.1m (£97.8m), up on the $151.5m loss it made in 2005. Its US revenues increased by 5.1% and international revenues fell 6.5%.
In the same month McCann Erickson announced suddenly it was to pull out of the pitch for Reckitt-Benckiser, due to client conflict. McCann Erickson was one of three agencies participating in the $1.2bn global Reckitt-Benckiser review, which was eventually won by Euro RSCG Worldwide.
Earlier this month Interpublic announced that its FCB and Draft networks were merging to form the Draft FCB Group.
The merger is expected to throw up further client conflicts for the group, which could see the departure of other much needed business. FCB currently handles SC Johnson and Motorola and Draft has Procter & Gamble and Nokia as its clients.
Head of Draft FCB and Draft's founder Howard Draft told Campaign last month that losing business as a result was "not something we're worried about," and denied that the merger was about cutting costs.
Draft said: "The move is totally the opposite of cutting revenues and costs. I have already told my staff to go out and hire the best creatives in the world."
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