X0305 4 2012-05-21 0001112412 ENDEAVOUR INTERNATIONAL CORP END 0001385897 STEELHEAD NAVIGATOR MASTER, L.P. MINTFLOWER PLACE, 4TH FLOOR 8 PAR-LA-VILLE ROAD HAMILTON D0 HM 08 BERMUDA 0 0 1 0 Common Stock 2012-05-21 4 S 0 213827 6.583 D 4104822 D Common Stock 2012-05-22 4 S 0 81133 6.5636 D 4023689 D Steelhead Navigator Master, L.P.; By: Steelhead Partners, LLC, its Investment Manager; By: Brent Binge, General Counsel; /s/ Brent Binge 2012-05-23