BG will invest at least 6 billion Norwegian crowns ($1 billion) in developing the Jordbaer field off Norway, rising to 11 billion crowns if more resources are found, the UK gas firm said on Thursday.

The field, discovered in 2008 and situated in the Norwegian part of the North Sea, may hold some 70 million barrels of oil equivalent, BG executives said as they submitted the field's development plan to Norway's energy minister.

"Recoverable reserves could reach 100 million barrels if (nearby) prospects prove successful," Marianne Eide, who heads the development of the project for BG, told reporters.

Jordbaer, which means Strawberry in Norwegian, is expected to come on stream in the autumn of 2013.

Operator BG holds a 45% stake in the field, Japan's Idemitsu Kotsan has 25%, Germany's RWE Dea has 20% and BASF-owned Revus Energy holds the remaining 10%. Production at Jordbaer will last between six and 20 years, according to the development plan filing to the Norwegian energy ministry.