Norwegian energy company Statoil said Monday it was postponing a development decision for the multi-million barrel Johan Castberg reserve area.

Statoil, along with its partners -- Italian energy company Eni and Norway's Petoro -- said it decided to review its concept for Johan Castberg reserve area in the Barents Sea.

"The companies will continue efforts to mature the technical development solution, updating the resource basis and reducing cost leading up to the summer of 2015," Arne Sigve Nylund, Statoil executive vice president for Norwegian development and production, said in a statement.

Statoil, which serves as the operator of the reserve area, said it estimated the proven reserves at Johan Castberg at between 400 million and 600 million barrels of oil.

The Norwegian company said it's carried out an extension exploration campaign in the Barents Sea field in order to prove Johan Castberg is a viable project.

"Unfortunately, the exploration campaign has proven less new oil resources in the Castberg area than expected," Nylund said. "In total, we have not proven enough resources in Castberg to make the field viable for supporting infrastructure, including a pipeline to shore and an onshore terminal on its own."