LONDON, Sept 20 (Reuters) - The Organization of the Petroleum Exporting Countries (OPEC) has opted to postpone an in-person meeting to celebrate its 60th anniversary from Sept. 30 to early 2022, a source from the group told Reuters, citing a letter.

OPEC sent out invitations in June for the event with the hopes of holding an in-person meeting, which would have been the first the group has since March 2020, but sources said coronavirus restrictions came in the way.

(Reporting by Alex Lawler, writing by Ahmad Ghaddar; editing by David Evans)