* Trading was choppy, with the market fluctuating between positive and negative territory throughout the day. * MGEX spring wheat bucked the overall downward trend, finishing higher amid concerns that poor soil moisture in the northern US Plains would hamper crop production this year. * Traders and analysts were expecting the USDA report to show wheat ending stocks for the 2011/12 crop year slightly smaller than previously projected. * Spanish buyers bought about 200,000 tonnes of wheat from the United Sates in the past week due as supplies from eastern European countries have become scarce, traders said. * Tunisia bought 50,000 tonnes of optional-origin soft wheat in a tender for shipment in March or April. * Syria rejected all offers in international tender to buy 100,000 tonnes of soft milling wheat, European traders said.