The price of Brent crude oil dropped today as focus returned to negotiations over a nuclear deal between Iran and six world powers.

Reuters reported that Brent crude was down 37 cents to $56.73, and US crude dropped 50 cents at $49.59 a barrel.

The parties have extended talks on Tehran’s nuclear programme into a second day past a deadline of 31 March.

"Slower growth in inventories is signalling that production is finally catching up to the recent decline in the US rig count."

Citing diplomats, the news agency said possibilities for a preliminary agreement were balanced between success and collapse in the coming hours.

US Secretary of State John Kerry and German Foreign Minister Frank-Walter Steinmeier said they would stay at least until Thursday in Lausanne, Switzerland to seal a political agreement with Iran.

The nuclear deal is expected to ease sanctions and allow more Iranian crude into world markets.

Meanwhile, data from the Energy Information Administration (EIA) that US production fell for the first time since late December.

Crude inventories have, however, increased last week to a record high for the 12th straight week.

Analysts at ANZ were quoted by Reuters as saying, "Slower growth in inventories is signalling that production is finally catching up to the recent decline in the US rig count."