Veolia bought a 29.9% stake in Suez in October from utility Engie as a prelude to its full takeover offer. Suez managers have opposed the bid, prompting legal challenges from both sides.

Veolia said it would pay 18 euros per share for the 70.1% of capital it does not own. The price, unchanged from its initial offer, values Suez at 11.3 billion euros ($13.90 billion).

Suez shares were up 1.2%, at 16.84 euros, one hour after the Paris market open, while Veolia shares gained 1.8%.

"Our offer is the best option for Suez and for its shareholders. Despite market rumours, no real alternatives have been presented to Suez shareholders over the past five months since we first launched our project," Veolia said.

"Now is the time for the Suez board and management team to cease their destructive stalling tactics, act in the interest of all shareholders and allow them to vote on our offer?", it added.

Veolia said it had handed its pre-notification to the European Commission on Nov. 25 regarding its intentions to buy Suez.

(Reporting by Benoit Van Overstraeten. Editing by Mark Potter)