PARIS, Jan 15 (Reuters) - A French court ruled on Friday it was incompetent to decide on whether water and waste management company Veolia has to consult unions on its planned takeover of smaller rival Suez, the two groups said in separate statements.

Suez and unions at the company said that the ruling means that the consultation process with staff's representatives, that blocks Veolia's voting rights in general meeting, would run until May 31.

Veolia stuck to its stance that the consultation process will end on Feb. 5 before the company can move further in a full takeover of Suez.

The company added that additional judicial rulings on the consultation process were expected in February and March.

Veolia bought last year a 29.9% chunk of Suez from French utility Engie in a prelude to a takeover offer for the whole group that has been contested by Suez managers and led to legal challenges from both sides.

The company sent last week to the board the offer proposal it intended to file for the 70.1% of the company's capital it does not own. (Reporting by Benjamin Mallet and Matthieu Protard, editing by Louise Heavens)