The figure, similar to the implied 2021 stock draw of 406 million barrels seen a month ago by OPEC, is part of what one of the OPEC sources called a "healthy" supply and demand balance for 2021.

OPEC+ experts, the Joint Technical Committee, are meeting on Tuesday ahead of a ministerial meeting on Thursday to decide oil output policy.

(Reporting by Alex Lawler; Editing by David Goodman)