Opec production in May fell to 32.45mn b/d from 32.64mn b/d in April following severe outages in Nigeria stemming from terrorist attacks on oil infrastructure. There were also output dips in Venezuela, where the economy is in near-meltdown, Libya, and Iraq which fell from near-record levels in April.

These declines outweighed production boosts from Opec heavyweights Saudi Arabia and Iran, which increased their output in May to 10.20mn b/d and 3.42mn b/d respectively from 10.18mn b/d and...