Southeastern Europe 's largest aluminum producer Aluminum SA has secured a long-awaited commercial license for its cogeneration power plant, allowing it to sell electricity on the Greek market, the chairman of the conglomerate that owns the company said Tuesday.

"We have a license. It has taken us five years, but we have one," Mytilineos Holdings SA Chairman Evangelos Mytilineos told Dow Jones Newswires in an interview.

The 334-megawatt cogeneration plant was completed in 2008 at a cost of EUR200 million. Cogeneration is the simultaneous production of heat and electricity, using natural gas. The process is considered particularly energy-efficient and has been backed by the European Union.

For Aluminum SA--which produces 170,000 metric tons of aluminum a year at its integrated production facility in
Agios Nikolaos , Greece --the cogeneration plant has the potential to not only cut costs, but also generate profits.

While heat produced by the plant can be used in its alumina production process, the generated electricity can power its own operations or be sold to the Greek energy grid. Without a license to sell the electricity, though, the company previously had been able to use the plant's heat and electricity only for its internal operations. The commercial license was finally granted in February, Mr. Mytilineos said.

The delay in obtaining the plant's commercial license--partly due to a delay in
Greece 's adoption of European Union legislation on cogeneration--has cost the company dearly in estimated lost revenues, said Mr. Mytilineos.

The licensing delay "has cost us a lot of money--more than 100 million euros," said Mr. Mytilineos.