The development comes amid a continuing trend of consolidation in PR and increased talk of M&A deals.
Fleurot said he had no plans to appoint individual CEOs for the two networks, following the departures of Mark Hass and Eric Giuily from MS&L and Publicis Consultants respectively earlier this year.
'If I wanted this to be one network, the big mistake would be to hire one CEO for each,' said Fleurot. 'That would send the wrong message.'
Instead, Fleurot said the two agencies would co-operate across business lines. In countries where there is sufficient 'duplication', he added, they will either work together or one agency will be picked to lead.
'We need to join forces to match the critical mass of other global agencies,' he said.
Acquisition is also a priority, said Fleurot, as he attempts to expand a PR division that remains smaller than peers WPP and Omnicom Group.
Fleurot's comments come amid an upturn in PR-related M&A activity. Huntsworth Group has already bought healthcare shop Tonic Life Communications and Middle East player Momentum this year and is now believed to be seeking an agency acquisition in India.
Reports have also surfaced that Engine Group, owner of Mandate, is considering a stock market flotation to raise funds for acquisitions.
However, Bob Willott, director of financial research company Fintellect, ruled out a sudden surge of buying: 'There are quite a few companies that could do modest-sized deals but none of them will take too many risks until the end of the recession.'