Oil prices were narrowly mixed on Thursday as traders focused on events in the United States, the world's biggest consumer of crude, and on easing tensions over Iran.
New York's main contract, light sweet crude for delivery in June, fell ten cents to $104.02 a barrel.
Brent North Sea crude for June rose 21 cents to $119.33 a barrel in London midday deals.
"Oil prices have edged down (in New York) ... primarily because the market is reacting to the oil inventory report from the US," Victor Shum, an analyst at Purvin and Gertz energy consultants, told AFP.
Official data Wednesday showed US crude inventories had shot up by 23 million barrels over the past four weeks -- information that pointed to slack energy demand in the world's biggest economy.
Crude prices have won much support in recent months on Iran supply concerns but such tensions appeared to be easing, according to analysts.
"It would appear that progress has been made in the nuclear dispute with Iran," Commerzbank analyst Carsten Fritsch said in a note to clients Thursday.
"Apparently, Iran is willing to accept Russia's proposal that it undertake not to further expand its nuclear programme. In return, the EU should lift its oil embargo on Iran, set to come into force on 1 July."
Crude prices were meanwhile winning a little support Thursday from the Federal Reserve's decision to leave its key interest rate near zero, traders said. The US central bank on Wednesday said that growth would remain moderate over the coming quarters and then "pick up gradually."
