PARIS, April 20 (Reuters) - Investment funds Ardian and Global Infrastructure Partners will not participate in the deal to create a new French water company after the takeover of Suez by its bigger rival Veolia,, Ardian Infrastructure and GIP chief Mathias Burghardt told Reuters on Tuesday.

"Ardian and GIP will not take part in the new Suez project as it is," Burghardt said.

Veolia and Suez on April 12 announced a 13 billion euro ($15.66 billion) merger under which - in part to ease antitrust problems - some of Suez's assets will be spun off into a new entity with around 7 billion euros in revenue.

Investment funds Meridiam, Ardian and Global Infrastructure Partners as well as state-backed Caisse des Depots and employees were lined up to be shareholders in a "new Suez", which would mainly comprise Suez's French water activities and some international assets, including in Italy, Czech Republic, India and Australia.

Meridiam was set to own 40%, Ardian-GIP 40% and the others 20%, but a price for that carve-out has not yet been set.

Ardian-GIP, which in March had formulated a counter-proposal to the Veolia bid, had several important questions about the agreement, which is set to be finalised by May 14, a spokeswoman said earlier, confirming a report in newsletter La Lettre A.

In an interview with financial daily Les Echos, Ardian Infrastructure chief Burghardt had flagged his group would not take part in this project.

"The international part of the business of new Suez is insufficient to ensure its growth and boost its French activity," he said.

Ardian-GIP, which was not involved in the discussions that led to the deal, also regrets being assigned a minority stake and points at the hostility of Suez's unions to the agreement.

A source close to Veolia said that a possible withdrawal of Ardian-GIP would not jeopardise the deal.

"We are ready to take a bigger stake if we are asked," said a spokesman for Meridiam, which has previously said it was ready to acquire the split-off Suez water business on its own.

Suez shares closed 0.5% higher, outperforming Veolia shares, down 0.5%.

($1 = 0.8304 euros) (Reporting by Gwénaëlle Barzic; Writing by Geert De Clercq; editing by David Evans)