The company will now offer its shares at €16.50-€19.50 (£10.09-£11.92), compared with the planned price range of €21-€24.50 (£12.84 to £14.98). The offering, which was scheduled for today, will be postponed until Wednesday and trading is expected to begin on the Euronext Paris stock exchange on Thursday.
The family-owned company remained upbeat about the offering, however, and said it still expected to raise €1bn (£611.5m) to finance acquisitions and pay off debts. The number of shares on offer has been raised from 20% to between 23.9% and 27.4% of its capital in order to hit the target.
Founder Jean-Claude Decaux explained that recent developments in the market, particularly for companies in the media sector, made it increasingly difficult to "achieve a successful transaction in the initial indicative price range".
Some analysts had criticised the initial price range as being too high, given the uncertain conditions in the advertising industry.
The tough conditions were highlighted last week when two companies, the Interpublic Group of Companies and True North Communications, said they would miss second-quarter earnings estimates.
Publicis Groupe and Havas Advertising also saw their shares knocked lower amid fears of further downward revisions in the European media sector.