Johannesburg - Wheat in South Africa advanced the most in more than three weeks, following Chicago prices which rose on supply concerns from the Black Sea region as clashes intensified in eastern Ukraine.

The wheat contract for May delivery climbed 1.4 percent to 3,945 rand a metric ton, the biggest gain since March 20 by the close on the South African Futures Exchange.

Wheat for July delivery jumped 3.1 percent to $6.89 a bushel on the Chicago Board of Trade by 9:22 a.m.

Crisis talks with Russia, the US and the European Union are planned for April 17, as a United Nations Security Council meeting last night left the US and Russia trading blame for the unrest.

The EU is weighing expanding sanctions on Russia, which US Department of Agriculture data shows is the fifth-biggest wheat exporter, followed by Ukraine.

“International prices shot up this morning after increased tension in Ukraine over the weekend,” Brink van Wyk, a trader at Pretoria-based BVG Commodities (Pty) Ltd., said in an e-mailed response to questions.

While the nation is sub-Saharan Africa’s largest grower of wheat after Ethiopia, the country is still a net importer of the grain and usually follows the international benchmark price.

Ukraine is South Africa’s second-largest supplier of the cereal after Russia, accounting for 36 percent of imports since the current season started at the end of September, according to data on the South African Grain Information Service’s website.

White corn for delivery in July rose 0.6 percent to 2,106 rand a ton, while the yellow variety increased 0.7 percent to 2,216 rand a ton. - Bloomberg News