Benchmark European wheat futures eased on Friday to hit an eight-week low, pressured by weakness in Chicago in the run-up to a US government crop report expected to confirm ample global supplies despite a poor French harvest.
December milling wheat on the Paris-based Euronext exchange was down 1 euro, or 0.6 percent, at 158.75 euros a tonne by 1535 GMT. It had touched 158.25 euros earlier in the session, its lowest since July 15.
Euronext prices have been curbed by big harvests in North America and the Black Sea region, which have offset the slump in French production.
US futures eased after some export-fuelled gains this week, with attention turning to Monday's US Department of Agriculture (USDA) crop estimates.
Front-month September again saw volatile trading as market operators closed positions in the run-up to Monday's expiry of the contract.
It fell as much as 4 percent to a new contract low of 139.50 euros a tonne, the lowest spot price since 2010.
Some traders say the recent arrival of imported wheat in northern French ports that act as delivery silos for Euronext may have fuelled liquidation because operators fear contractual risks relating to the need to then re-export foreign wheat from a French port.
"People are selling as they wonder what's going to happen with delivery," one futures dealer said.
Monday will see CME Group launch rival European Union wheat futures. The exchange has added more delivery points, with 16 silos now lined up in northern France, Jeffry Kuijpers, CME executive director, agricultural commodities, told the Thomson Reuters online Global Ags Forum.
German cash market premiums in Hamburg were marked down amid weak demand.
Standard wheat with 12 percent protein content for September delivery in Hamburg was offered for sale at 1.5 euros over the Paris December contract, against 2 euros on Thursday. Buyers were seeking 1 euro over Paris.
"Demand is low, with the purchase in the Algerian tender on Thursday seen likely to be spread around several origins," one German trader said.
"Export demand is thin. A lot of Swedish wheat is available on export markets."
Prices were also curbed by expectations that there would be sufficient supply in Germany despite rain damage that would require the sorting and movement of grain between regions.
"Wheat will probably be transported over longer distances to regions that suffered rain damage, but overall there will be enough to go round," another German trader said.
"Strong German exports could generate imports from Poland, the Czech Republic and Slovakia to meet domestic needs."