Petroplus' Coryton refinery in the UK is operating at an unspecified rate and the UK administrator PwC is still in talks to secure fresh crude oil supply for the plant, a union official said on Tuesday.

The refinery is running normally and the administrator is trying to source crude, Russ Ball, regional industrial organiser for the trade union ,the plant was currently running at or the inventories of oil it held.

Swiss Petroplus, Europe's largest independent refinery by capacity, is filing for insolvency after battling with high debt and poor refining margins.

Three of its five refineries, Petit Couronne in France, Cressier in Switzerland and Antwerp in Belgium, have been shut this month.

(Reporting by Ikuko Kurahone; editing by James Jukwey and Jason Neely)