European leaders taking part in nuclear negotiations with Iran last weekend described the talks as constructive. Tehran said a mutual understanding was reached during negotiations in Istanbul but offered few specifics.
Iran is suspected of pursuing the technology needed to produce a nuclear weapon, an allegation the Iranian government denies.
Crude oil futures fell 0.9 percent on the New York Mercantile Exchange following the talks in Istanbul. David Lennox, a market analyst at Fat Prophets in Australia, told Bloomberg News that oil prices could dip to less than $90 per barrel for West Texas Intermediate crude.
"The flavor of those talks did seem a little more positive than the rhetoric of the past," he added.
The Organization of Petroleum Exporting Countries, in its monthly report, said geopolitical tensions rather than physical market disruptions were to blame for higher oil prices.
Bloomberg said crude oil for May delivery was around $102 in New York.