Royal Dutch Shell has called off a $410m (£199m) deal to farm into Ukrainian gas fields held by Regal Petroleum just one day after the controversial Aim-listed oil company announced a sudden change in management.

Europe’s biggest oil company this week agreed a memorandum of understanding with Regal for a 51 percent stake in the two fields. Analysts said the proposition was a good deal for Regal because Shell would have carried all the capital investment costs to develop the assets