Danish conglomerate Maersk Group has said the country's largest natural gas field is to close next year because the Tyra facilities in the North Sea "are approaching the end of their operational life".
Maersk Oil's executive Martin Rune Pedersen said the company "cannot safely continue production" despite reinforcements made over the past 15 years.
Mr Pedersen said no economically viable solution for continued operations has been found for the field which accounts for 90% of Denmark's annual natural gas production.
Maersk Oil operates the field, which opened in 1984, on behalf of British-Dutch oil multinational Shell and the Danish state, among others. Production is expected to cease on October 1.