UPDATE 1-Keep calm and don't waste time: Engie chairman tells Suez

(Updates with comments from Engie chairman)

PARIS, Sept 7 (Reuters) - French utility Engie’s chairman told the head of Suez “to keep calm” and get down to work quickly if he wants to present an alternative to a takeover offer by bigger rival Veolia which he dismissed at the weekend.

Water and waste management group Veolia offered to buy a stake in Suez from Engie and said it was willing to take over the rival, estimating its enterprise value at 20 billion euros ($23.7 billion).

On Sunday, Bertrand Camus, the head of Suez, dismissed Veolia’s offer as “disastrous” for France.

“I think we all need to keep calm,” Engie chairman Jean-Pierre Clamadieu told France Info on Monday.

“As I directly told Bertrand Camus, I think that if Suez wants to develop another project, we will study it as attentively. Simply, time matters and they need to get down to work very very quickly. Now, I think, they’ve started”.

A friendly deal between utilities Veolia and Suez may be possible, the head of French public lender CDC said on Monday, adding the creation of a “national champion” would be a “good thing”.

“The creation of a national champion seems a good thing in our view (...) It is possible that a friendly deal is in the works,” Eric Lombard said during a press conference.

CDC holds a 5.7% stake in Veolia and a 1.5% stake in Suez. ($1 = 0.8452 euros) (Reporting by Benjamin Mallet, Maya Nikolaeva and Benoit Van Overstraeten; Editing by Jan Harvey and Emelia Sithole-Matarise)