europa oil  gas plc union jack oil plc and egdon resources plc said monday that the north sea transition authority has approved the field development plan for the ukbased wressle oilfield the three energy and oilandgas companies hold a significant interest in the oil field europa oil  gas holds a 30 interest in the field while union jack has a 40 economic interest egdon resources on the other hand is its operator and holds a 30 interest the nstas approvalensures the wressle project remains on track to transition from an extended well test to production wressle continues to exceed our expectations generating high levels of production and revenues with the wressle1 well currently amongst the most productive in the onshore uk chief executive simon oddie said