European Union regulators would be able to ban abusive short selling of shares and naked selling of credit default swaps and sovereign debt for three months or more under a draft EU law seen by Reuters on Wednesday. The bloc's financial services chief, Michel Barnier, has already flagged the measure he is due to publish on September 15. It follows calls from some member states to crack down on what they saw as speculators -- typically politicians' code for hedge funds -- causing mayhem in Greek and other euro zone sovereign debt markets earlier this year.