Egypt, the world's biggest wheat buyer, said it will exclude Russian grain from its tenders for now.

This is a sign the exporter is failing to win back some customers after imposing a 10-month ban on shipments, reported the San Francisco Chronicle.

Russia, once the second-largest wheat exporter, plans to resume shipments from July 1 after the government predicted total grain output may rise as much as 48 percent this year. While the country has 4 million metric tons of last year's wheat crop available for export, as much as 2 million tons of it may not be of a good enough quality to ship, according to the Grain Union, the largest lobby group for cereal exporters.

"Last year the Russians failed to ship some quantities that were agreed upon even before the ban came into effect, and that is why I am wary of the Russian side," Nomani Nomani, vice chairman of Egypt's state wheat buyer, the General Authority for Supply Commodities, said. "When we are sure that the Russian side is stable, we will re-include it."

Wheat traded in Chicago, a global benchmark, rose as much as 89 percent in the past 12 months as drought and flooding from Canada to Russia to Europe ruined crops.

Russia's return to the export markets comes as weather threatens crops again in the U.S. and across Europe, where some farmers are contending with the driest growing season in more than three decades.

The UK, the European Union's third-biggest wheat producer, declared droughts in some grain-growing regions on June 10.