* Wheat 1.4% higher on Black Sea security risks
* Funds short covering push wheat higher
* Corn, soybeans unchanged on weather uncertainty in Brazil
(New throughout, updates prices, market activity, US trading comments; changes dateline, previous PARIS/SINGAPORE)
CHICAGO, Dec 28 (Reuters) - Chicago wheat futures climbed on Thursday after a vessel hit a mine in the Black Sea, an incident that underscores the continuing security risks along the key global grain trade shipping route.
Corn and soybeans were relatively unchanged as traders assessed uncertainty over how much the rainy forecast in South America will benefit drought-affected crop belts in Brazil.
The most-active wheat contract on the Chicago Board of Trade (CBOT) was up 1.4% at $6.32 a bushel by 10:30 a.m. (1630 GMT).
A bulk carrier that was headed to a River Danube port to load grain hit a Russian mine in the Black Sea on Wednesday, injuring two crew members, Ukrainian officials said on Thursday.
The contract was pushed higher by funds short covering their positions along with the Black Sea news, said Joe Davis, director of commodity sales at Futures International.
"It's been back and forth this whole week. It's a holiday week, so it's low volume. So any type of flow is going to be more pronounced in a low-volume trade," he said.
Traders said market reaction to such incidents tended to be short-lived given disruption to maritime traffic, including through a Black Sea corridor established by Kyiv, has been limited.
The wheat market was also reacting to Egypt's state grains buyer the General Authority for Supply Commodities (GASC) saying on Thursday it had cancelled an international tender for wheat with no purchase made. Traders said they believed prices offered were regarded as too high.
CBOT corn was down .05% at $4.76-1/4 a bushel and soybeans added 0.02% to $13.20-3/4 a bushel.
Weather charts showed uneven showers in the week ahead in dry parts of central and northern Brazil, one of the top global corn and soybean producers, before widespread heavy rain expected in early January. (Additional reporting by Gus Trompiz in Paris and Naveen Thukral in Singapore, editing by Alexandra Hudson)
