Output by OPEC oil producers has reached record levels, the International Energy Agency said Thursday, raising fears a global oil glut will continue to weigh on markets unless the cartel agrees on a cut.

Production by the 14 members of the OPEC cartel rose to "a record 33.83 million barrels per day in October", the IEA said, ahead of November 30 talks in Vienna aimed at hammering out a deal to curb production.