LONDON, May 21 (Reuters) - European Union regulators are considering tougher scrutiny of foreign bank branches in the bloc whose ranks have been swelled by Brexit to create “negative risks”, sources familiar with the discussions have said. The bloc’s European Banking Authority gave a presentation to EU officials earlier this month setting out the rapid growth in third country bank branches, the sources said. (Reporting by Huw Jones, editing by David Evans) Our Standards: The Thomson Reuters Trust Principles.