* The benchmark Chicago Board of Trade March soft red winter wheat contract fell below a key technical support level at its 50-day moving average for the first time in three weeks. * Light precipitation in the form of rain and snow expected in the US Southern Plains hard red winter wheat region over the next week to 10 days. No signs of a threat to the crop from cold weather, said Drew Lerner, meteorologist for World Weather Inc. * Saudi Arabia announced a tender to buy 330,000 tons of hard wheat for shipment in May and June. * Ukraine has no plans to curb exports of grain despite risks of crop-loss due to adverse winter weather, Agriculture Minister Mykola Prysyazhnyuk said. * Analysts expecting weekly US Agriculture Department report on Thursday morning to show export sales of wheat in range from 450,000 to 650,000 tonnes compared to 707,800 tonnes last week.