Four parties have expressed interest in the controversial sale of 51% of Thessaloniki's water company EYATH, including French company Suez and a citizens' collective, Greece's news agency said on Tuesday.

Greek privatisation agency HRADF announced that the first phase of the tender had been completed and that the four candidates will be evaluated, without revealing their identities.

The sell-off of EYATH, scheduled to be completed this year, is part of a long list of privatisations demanded by Greece's European Union and International Monetary Fund creditors.

The Greek state currently owns 74 percent of the shares of EYATH, the country's second-largest water company.

According to the state-run Athens News Agency, EYATH has attracted the interest of a consortium comprising France's Suez Environment and Greek company Ellaktor, owned by Greek public works and media baron George Bobolas.

Another consortium including Israel's Mekorot water company as well as Greek-Russian businessman Ivan Savvidis, who in 2012 purchased Greek football club Paok, have shown interest.

The so-called Movement 136, an activist collective opposing the company's privatisation, has also made a bid.

The collective proposes management through cooperatives operating at the neighbourhood level.

The Thessaloniki municipal council meanwhile has called for a referendum on the company's privatisation, which it also opposes.