US focused oil group Nighthawk has sold its 50% interest in the Centurion project in Kansas to Osceola Hydrocarbons for $5m in cash.Nighthawk will also be paid an annual royalty equal to 5% of the gross oil and gas revenues from the Centurion project."We are pleased to have executed the sale of our interest in Centurion, a non-core project," said Nighthawk's managing director David Bramhill."As the evaluation and development of Jolly Ranch and the Waterflood projects continue, we are confident that these core projects will enable the company to achieve the internal goals that have been set in terms of reserves and production potential."