LONDON  - US. soybean futures edged up on Tuesday, approaching the prior session’s seven-week peak, buoyed by concerns about unfavourable weather in South America, although the advance is likely to face stiff resistance around $15 a bushel.Corn and wheat prices were little changed with the slow current pace of US. exports keeping a lid on both markets.Rabobank analyst Erin FitzPatrick said the most serious concerns centred on less than ideal rainfall in southern Brazil, across Paraguay and Argentina with the weather forecast to be remain unfavourable for the next 7 to 10 day period.“This is causing a lot of people to downgrade their expectations for the crops, particularly in Argentina,” she said, adding there were also concerns about too much rain in northern Brazil where the harvest is getting underway.Chicago Board of Trade March soybeans rose 1-1/2 cents or 0.1 per cent to $14.90-1/4 a bushel by 1224 GMT. The contract touched $14.98 on Monday, its highest level since mid-December.CBOT March wheat gained a marginal 3/4 cent or 0.1 per cent to $7.63-3/4 a bushel and March corn stood 1/4 cent or 0.03 per cent lower at $7.34 a bushel.Milling wheat futures in Paris were slightly lower with March off 0.75 euros or 0.3 per cent at 246.75 euros a tonne with a rise in the euro, after a sharp fall on Monday, exerting downward pressure on prices.News that Russia’s government backs a plan to suspend a grain import duty had little impact on the market, with operators waiting to see when the measure would be implemented and what import volumes it could trigger.Potential suppliers could include Europe, South America and the United States.“I would think Europe should be the most competitive and of course delivery is quicker,” said Wayne Bacon, president of grain trader Hammersmith Marketing.RESISTANCE TO $15 BEANSRabobank’s FitzPatrick said there was likely to be resistance around the $15 level for soybeans and anticipated consolidation around current levels but the market should eventually continue to rise given the weather in South America.“We are very close to some technical resistance levels in beans and fund positioning has increased substantially over the past week,” said Victor Thianpiriya, an agricultural strategist at ANZ in Singapore.Reuters analyst Wang Tao said he expected March soybeans to retrace to $14.69-1/2 per bushel, as they have failed to break a resistance zone of $14.98-1/2 to $15.01-1/4.Dry weather will resume this week in Argentina’s main crop belt after limited showers fell on soy and corn plants over the weekend, a local weather specialist said Monday.Brazilian agricultural analysts AgRural and Celeres cut their forecasts for the country’s soybean crop on Monday because of irregular rains in some growing areas.AgRural lowered its December forecast by 1 million tonnes to 81.2 million tonnes. Celeres said the crop would likely yield 80.1 million tonnes, down from its January forecast of 80.84 million tonnes.At the same time, demand from China, the world’s top importer, continues to remain strong. The US. Department of Agriculture confirmed on Monday private sales of 116,000 tonnes of US. soybeans to China, with 58,000 tonnes for shipment in the marketing year ending Aug. 31.“We’ve had record high exports coming out of the US., we’ve also seen fairly strong demand domestically for soybean crush in the US., so any logistical delays or further downgrades to South American production are going to have an impact on US soybean supplies if demand continues at this very strong pace,” Rabobank’s FitzPatrick said.Dealers said US. export activity was subdued in both wheat and corn, in contrast to soybeans.An estimated 5.348 million bushels of corn and 15.206 million bushels of wheat were inspected for export in the week ended Jan. 31, USDA said. That was below trade estimates for inspections of 15 million to 20 million bushels of corn and 20 million to 25 million bushels of wheat.Commodity funds sold a net 4,000 CBOT corn contracts on Monday, trade sources said. They sold 3,000 wheat and bought 5,000 soybean contracts.