China has bought around 10 to 12 cargoes of mainly U.S. corn in the past month and is set to step up purchases as a record gap between domestic and international prices encourages buyers to seek out cheap imports. Overseas purchases by the world’s second-largest corn consumer had plunged in the second half of last year, after domestic supplies became much cheaper following an overhaul in farm policy. But healthy demand for animal feed and industrial processing, and concerns over supplies have kept Chinese prices relatively high for much of this year, and a rally in recent weeks has helped to push the spread with Chicago corn prices to a record.