* CBOT March corn settled down 6-1/2 cents at $3.75-1/4 per bushel, the lowest since Nov. 30 and the steepest percentage drop in nearly two months.

* Rainy weather in dry areas of key exporters Brazil and Argentina are boosting crop production prospects.

* Concerns about slowing demand for corn from the ethanol industry, which consumes about one-third of the US harvest, weighed on prices. Tumbling energy prices have eroded ethanol production margins.

* Traders are watching for signs of demand from China after the country negotiated a 90-day truce in its trade war with the United States which could include Chinese purchases of US corn and other agricultural products.

* The US Department of Agriculture said corn export sales last week totaled 2.517 million tonnes, within analysts' forecasts for 2.3 million to 2.9 million tonnes.

* Additionally, the USDA said private exporters sold 373,455 tonnes of US corn to Mexico for shipment in the 2018/19 season and 53,345 tonnes for shipment in 2019/20.