PARIS, April 11 (Reuters) - Suez LYOE.PA Chief Executive Gerard Mestrallet called on Friday for a common energy policy and a single regulator in Europe, but said this would probably take time.
Mestrallet also reiterated his opposition to plans by the European Commission to separate energy production and transport networks.
"We need to go further in the creation of a big European energy market. I am in favour of a single regulator. This would be gradual with a common regulator (supervising national regulators) and then a single regulator," Mestrallet told a press briefing.
However, Mestrallet said he did not expect this to happen "overnight" because electricity rules were still different from one country to the other.
"If we really want a big market, we need these rules to be the same and we need a single cop," he said. "We don't know what Europe's long-term vision is on electricity production ... For the moment, it's as if every one is acting in a scattered way."
Asked whether the lack of European harmony stemmed from the opposition of countries such as Germany to nuclear power, Mestrallet said: "This makes things harder but not impossible."
"I don't see why Europe would not clearly accept the nuclear option while leaving each country free to opt or not for nuclear power."
Europe could set more ambitious targets to fight global warming should it accept nuclear power as a carbon emission-free energy source, Mestrallet said.
"Europe set a goal of 20 percent of renewable energies (in total power production) and left nuclear aside," he said.
"I think we could be more ambitious in terms of fighting global warming without making a useless distinction between the good energies and those whose name we cannot mention."
France is Europe's biggest nuclear power producer, with EDF (EDF.PA) operating 58 reactors. Suez operates two nuclear plants in Belgium through its Electrabel subsidiary.
Aside from cutting emissions by at least one-fifth by 2020 from 1990 levels, EU states have agreed to use 20 percent of renewable energy sources in power production and 10 percent of biofuels from crops in transport by the same date.
Mestrallet reiterated his opposition to EU unbundling plans, calling the move "useless". He said separating production and transport networks was unlikely to solve competition issues.
Europe has made the choice of liberalising the energy market, thinking that this alone would bring prices down, without taking into account the fact that production capacities were becoming insufficient, Mestrallet said.
Europe needs to invest some 1,000 billion euros ($1,582 billion) in the energy sector by 2030 to meet consumers' needs, he added. (Editing by Mike Elliott)