Publicis, the world's sixth-largest advertising and communications group, acquired Saatchis for $1.9bn (£1.3bn) in September last year, adding clients such as Toyota and Procter & Gamble.
The Paris-based group said it had won €1.5bn (£945m) in new business in the first six months of the year, including Siemens and Adidas-Salomon in Japan.
Chairman Maurice Levy said in a statement that the group does not expect any spectacular improvement in the second half, but "we believe that advertising spending could pick up again due to some particular segments such as retail and cars".
The group said that a cost-cutting strategy, which it implemented during the first half, has prompted a rise in organic growth, particularly in the US where it has made significant savings.
Organic growth rose 5% in the US, 8.2% in Europe, 2.7% in the Asia-Pacific region, and 7.1% in Latin America and the rest of the world.
Shares in Publicis began to climb slightly this morning to €26.92 (£16.99) from its close of €26.88 (£16.96) on Friday, which was down 5.1% on the day. The group's share price has dropped 25% this year.