"We have to adopt ourselves to the new world and this is what I think we have done. I think that concentration has some merits and it has some drawbacks. When you look at the bottom line, it is extremely positive that we see some great player s in this world," he added.
(Read more: Publicis CEO talks merger & future of advertising at CES)
Publicis reported fourth-quarter earnings that fell short of annual growth targets after a slowdown in emerging markets, particularly in China and India, where the group is overexposed to the luxury goods market said Levy.
Publicis said organic revenue, a closely tracked figure in the industry which strips out acquisitions and currency swings, rose just 0.7 percent in the three months ended December, dragged down by an 11 percent fall in China. Full-year organic growth stood at 2.6 percent for revenue of 6.95 billion euros. Analysts were expecting 3 percent organic growth, investment bank UBS said.
(Read more: The $35 billion Publicis-Omnicom merger 'started as a joke')
However, the firm still posted an overall rise in full-year net profit to 792 million euro ($1.08 billion) from 732 million euros in the prior year, despite some costs related to the upcoming merger.
Levy said the delays to the $35 billion merger with Omnicorp, which was announced in July 2013, due to issues obtaining antitrust clearance from China will push the closing date into the second half of this year.
"There is nothing major, just administrative process which is taking a bit of time. Will it close in H1, or the beginning of H2 – it is very difficult to say, it is very possible that it will be slipping to start of H2. I don't see the problem with some delays in a merger of this size," he added.
—By CNBC's Jenny Cosgrave: Follow her on Twitter @jenny_cosgrave