Moscow/ Sochi, Russia - German ex-chancellor Gerhard Schroeder said Thursday 100 million euros were being spent on an environmental study of the Nord Stream pipeline project for gas from Russia to Germany, which he chairs.

"The most acute problems for the realisation of the Nord Stream project are of course issues over ecological preservation," Schroeder was quoted by Interfax news agency as saying.

He made the comments at a meeting with Russia's premier Vladimir Putin and the head of national energy Gazprom Alexei Miller in the Black Sea resort of Sochi.

Objections from Estonia, Poland, Sweden and Finland over the environmental damage of the planned pipeline along the Baltic Sea basin have driven up the cost of the project and raised concerns over delays.

But "There are no doubts today, that the project will be realised by the end of 2011," Miller declared Thursday, adding the pipeline should furnish gas to 25 million homes in Europe.

Putin, in turn, hailed Nord Stream as a "pan-European" venture highlighting that five European countries - Germany, France, Great Britain, the Netherlands and Denmark - have already signed onto the project.

But plans for the 1,200-kilometre pipeline feeding directly to Germany have raised fears of increased energy dependence on Russia at a time when poor relations over the war in Georgia have renewed calls among European member states backed by the United States for alternative energy suppliers.

State-run Gazprom owns 51 per cent of Nord Stream pipeline with Wintershall and EON Ruhrgas each holding 20 per cent and Nederlandse Gasunie 9 per cent. (dpa)