By Julia Payne LONDON (Reuters) – Tanker and barge shipments in and out of Europe’s biggest oil hub have been delayed by up to a week as four storage companies scramble to resume operations after cyber attacks, sources familiar with the matter said. Since the end of last week, storage company Oiltanking and oil trading firm Mabanaft, both owned by Germany’s Marquard & Bahls, have been hit by hackers. Belgium’s SEA-TANK and Dutch fuel storage firm Evos have also been affected. The companies have had to suspend some operations, affecting oil flows in the Netherlands, Belgium and across Germany. …