CHICAGO / SAO PAULO / REUTERS Brazil will wrest the mantle of the wor ld s top soybean exporter from the United States in the coming year, in the latest sign of America s slowly diminishing role in global food trade.

Just months after data showed the United States would supply less than half of all corn exports for the first time in 40 years, revised Department of Agriculture forecasts put Brazil as the No. 1 exporter of soybeans for the first time in six years and the second time ever.

Both milestones illustrate how ethanol has constrained U.S. export growth, and how emerging economies with vast fallow land are strengthening their ties with China, which buys nearly two-thirds of the world s soybeans.

And with Brazil poised to expand soybean production, China may be the beneficiary. Several years ago, China refused delivery of several cargoes of soybeans from Brazil, claiming they were of poor quality. However, U.S. traders said it was a ploy to renegotiate prices, which had fallen sharply since the purchases had been made.

China, which had begun importing significant quantities of corn from the United States, buys 60 per cent of all the soybeans traded around the globe.