The world's biggest oil exporters in Opec are pumping almost two million barrels per day (bpd) more crude than required, the highest surplus for at least a decade, data from Reuters, top forecasters and energy agencies shows.

The Organization of the Petroleum Exporting Countries produced 30.27 million bpd in the first quarter of this year, Reuters data shows. The cartel is expected to pump even more, around 30.36 million bpd, in the second quarter, the US government's Energy Information Administration (EIA) projects.

Analysts say Opec's key members, including Saudi Arabia, Iraq, Kuwait and the UAE, have increased production in recent months in an attempt to build market share ahead of the possible lifting of economic sanctions on Iran.

But demand for Opec's oil is way below that level. It averaged just 28.34 million bpd in January-March and is expected to be only fractionally higher at 28.37 million bpd between April and June, major forecasters including Opec and the International Energy Agency say.

That leaves a surplus of 1.93 million bpd in the first quarter and 1.99 million bpd in the second - the highest oversupply for at least a decade, pushing oil inventories in many parts of the world to record levels.

US crude oil inventories hit an all-time high of 489 million barrels in the week to April 17, EIA data showed.-Reuters