[NEW YORK] Oil prices fell on Monday as the market weighed last week's Opec meeting and the prospects for a breakthrough in upcoming nuclear talks with Iran.
US benchmark West Texas Intermediate for delivery in July lost 99 cents at US$58.14 a barrel on the New York Mercantile Exchange.
In London, European benchmark Brent oil for July delivery shed 62 cents at US$62.69 a barrel.
Investors were mulling the impact on prices after the 12-nation Organisation of the Petroleum Exporting Countries (Opec) on Friday defied calls to cut output despite the big drop in crude prices since last year.
"With the Opec meeting behind us, investors will be searching for a catalyst to provide direction for oil prices," said Morgan Stanley analysts in a research note.
Michael Smith, president of T&K Futures and Options, said the oil market would remain stuck in a range of US$55-$63 a barrel until there is a clearer catalyst, such as a surprise drop in oil production or major progress on Iran.
Six global powers - Britain, China, France, Germany, Russia and the United States - are trying to nail down a deal to curb Iran's nuclear ambitions by reducing its stockpiles of enriched uranium and mothballing some of its sites.
If the agreement is reached and implemented, the powers will gradually scale back sanctions, allowing Iran to export much more oil than it does now.
"Any likelihood of a deal could act as a trigger for downward movement of crude prices," said Sanjeev Gupta, head of the Asia-Pacific oil and gas practice at business consultant EY.