Brent oil futures retreated from the highest close in more than a month on speculation that this week’s gains have been excessive amid concern that a global economic slowdown may curb demand.

Futures fell as much as 1.4 percent after rising about 9 percent since June 28. Societe Generale SA cut its crude-price forecasts, citing ample supply amid Europe’s debt crisis and a slowing Chinese economy. Iranian and European officials met in Istanbul today to discuss differences over the country’s nuclear program. A mediator called oil workers to talks aimed at resolving Norway’s first industrywide strike since 2004. U.S. floor trading will be shut for the Independence Day holiday.

Brent crude for August settlement was down as much as $1.42, or 1.4 percent, at $99.26 a barrel on the ICE Futures Europe exchange in London. It trimmed losses to trade at $99.86 as of 12:02 p.m. local time. The European benchmark was at a premium of $13.12 to West Texas Intermediate crude in New York versus $13.02 yesterday.

West Texas Intermediate oil for August delivery fell as much as $1.16 to $86.50 a barrel on the New York Mercantile Exchange. The contract increased yesterday by $3.91 to $87.66 a barrel, the highest close since May 30. Prices have lost 12 percent this year.