LONDON- Harbour Energy on Thursday said that net reserves at the Tolmount UK North Sea gas project could be downgraded to between 20 million and 30 million barrels of oil equivalent (boe), according to preliminary estimates.

This would be 25-50% lower than expected when the project received a final investment decision, a presentation slide showed.

(Reporting by Shadia Nasralla Editing by David Goodman ) ((Shadia.Nasralla@thomsonreuters.com; +44 778 99 43141; Reuters Messaging: Reuters Messaging: shadia.nasralla.reuters.com@reuters.net))