BRUSSELS, March 4 (Reuters) - The European Union is planning to extend its export authorisation scheme for COVID-19 vaccines to the end of June, two EU sources told Reuters on Thursday, in a move that could reignite tensions with countries who rely on shots made in the EU. The mechanism was set up at the end of January as a reaction to vaccine makers’ announcements of delays in the deliveries of COVID-19 vaccines to the EU. It is due to expire at the end of March, but the European Commission wants to extend it through June, the two officials said. “The Commission will propose its extension into June. And that was greeted by the member states with approval, not necessarily enthusiasm, but there is a feeling that we still need that mechanism,” one senior EU diplomat said. The second official added that at a meeting with EU diplomats on Wednesday, many countries supported the measure, including heavyweights Germany and France. The EU Commission was not immediately available for a comment. (Reporting by Francesco Guarascio @fraguarascio and John Chalmers; Editing by Toby Chopra)