Wheat and corn up by daily maximum after Ukraine attacks

Wheat and soybeans hit highest since 2012; corn jumps to eight-month peak

US wheat and corn futures rose by their daily trading limits on Thursday, while soybeans reached the highest level since 2012, after Russian forces attacked Ukraine, exacerbating worries over global supplies.

Wheat rose for a third day, scaling its highest in more than nine years, while corn climbed to an eight-month peak.

Shortly after Russian President Vladimir Putin spoke in a televised address on state TV on Thursday, explosions could be heard in the pre-dawn quiet of the Ukrainian capital of Kyiv.

"Heightened tensions around Russia-Ukraine and a fair amount of uncertainty over Russian supplies over the coming months have prompted traders to keep their grain at home rather than shipping it overseas," ING commodity strategists said in a note.

With Russia and Ukraine accounting for about 29% of global wheat exports, 19% of world corn supplies and 80% of world sunflower oil exports, traders were worried that any military engagement could hamper crop movement and trigger a mass scramble by importers to replace supplies from the Black Sea region.

"Russia-Ukraine tensions exacerbated supply risks for the global market," the ING strategists said as they cited still-muted wheat exports from the European Union.

The most active May wheat contract on the Chicago Board of Trade soared 5.7% to $9.34-3/4 a bushel, the highest since July 2012.

Corn climbed by up to 5.1% to $7.16-1/4 a bushel, its loftiest since June 10.

May soybeans were up 4.2% at $17.41 a bushel at 0846 GMT, advancing for a sixth session. Earlier in the day, it hit its highest since September 2012 at $17.56-1/2.

Russia has suspended movement of commercial vessels in the Azov sea until further notice but kept its ports in the Black Sea open for navigation, its officials and five grain industry sources said, as news of Russia's attack on Ukraine rattled markets.

In China, soymeal futures on the Dalian Commodity Exchange rallied to a record high even as the government plans to release soybeans from reserves amid worries over tight supplies in the market.