By Ed Ballard 

LONDON--Agricultural dealers said shipments of wheat to Turkey from key Russian ports were put on hold amid continued tensions between the two countries.

Russia on Thursday announced plans to impose sanctions on Turkish economic interests, including trade. Uncertainty over how that dictate will translate in practice led port officials on Friday to stop granting crucial customs approvals for shipments of wheat bound for Turkey from ports on the Azov Sea, where the bulk of the countries' grain trade is handled, two brokers said.

Any impact on wheat prices globally is expected to be short-term. But the disruption is high stakes for both countries. Russian wheat sold to Turkey is one of the biggest trades between the two nations.

Wheat exports appear to be on hold until Monday at the earliest, the brokers said, as port officials await word of Moscow's sanctions policy. Neither Russian government nor port officials were reached for comment.

Erol Yahya, executive director of Turkish milling group Intermil-Un, said Friday his company had suspended new purchases of Russian wheat until the situation becomes clear. Meanwhile, a trader and brokers say, some Russian trade houses have stopped finalizing new deals with Turkish buyers. The sellers are afraid that an extended export ban would leave vessels stuck in port accruing fines, said Andrey Sizov, managing director of Russian agriculture consultancy SovEcon.

The paralysis comes after some ships were permitted to leave with wheat cargoes on Thursday, according to Mr. Yahya and the director of a Dubai-based brokerage that handles wheat exports from the region.

"It's a mystery to us what's going to happen," said Gregory Souris of Actava Trading DMCC, the brokerage.

A Turkish jet fighter on Tuesday shot down a Russian bomber along the Syrian border, marking the first time a North Atlantic Treaty Organization member downed a Russian warplane since 1952.

Russia is the biggest supplier of wheat to Turkey, according to March report from the U.S. Department of Agriculture. More broadly, Russia is the world's third-largest wheat exporter, and Turkey is one of its biggest customers.

Turkey bought around 1.6 million metric tons of Russian wheat in three months through October, making it Russia's second-largest buyer after Egypt. Turkey could be facing higher wheat prices if it needs to find alternative sources.

Sizable wheat reserves give the global market a large cushion against volatility from the situation. European wheat prices are down 12% this year, and this week European wheat futures shrugged off the geopolitical turmoil, with contracts for March 2016 delivery in March 2016 falling under 1% to EUR181.50 ($192.25) a ton on Friday.

After three consecutive big harvests, this marketing year will end with stocks of around 209 million tons of wheat stockpiled, according to the International Grains Council.

Any disruption would come as a boon to the beleaguered grain industry in U.S. and elsewhere in Europe, giving producers a chance to sell some of the millions of tons of grain piling up in silos around the world.

Additional demand from Turkey could comfortably be met by Russia's rivals, said Daryna Kovalska, an analyst at Macquarie, although a short-term price-spike is possible if Turkish millers have to scramble to find alternative sources of wheat at short notice.

Mr. Yahya of Intermil said his company would have pay $30 to $40 more per ton for wheat from Canada, Australia or the U.S. if it were cut off from Russian supplies, he said.

Many in the industry are hoping that the two governments will quietly permit trade to continue even as they spar in public, citing the countries' mutual dependence in trade. Mr. Sizov, of the Russian agriculture consultancy, said a formal ban would be counterproductive in light of the revenue Russia receives from sales of wheat to Turkey.

Turkey was the No. 1 destination for Russian wheat, corn, sunflower oil, and sunflower meal in 2014-15, accounting for exports worth around $1.5 billion dollars, according to SovEcon's data. Meanwhile, Russia's boycott of some EU products has left it reliant on imports of fruit and vegetables from Turkey.

Logistical factors also would hinder the two countries if they sought alternative arrangements, Mr. Yahya says. The ports of the Azov Sea--the northern part of the Black Sea--are set up to serve small vessels of 3,000 or 5,000 tons. As such, they are well-suited to Turkey's importers, who prefer small shipments because of the higher costs involved when the 60,000-ton vessels used at larger ports encounter delivery problems, he said.

Write to Ed Ballard at ed.ballard@wsj.com

(END) Dow Jones Newswires

November 27, 2015 19:04 ET (00:04 GMT)