Japan and Mexico are expected to curb their purchases of U.S. corn after a buying spree in February pushed prices to their highest levels since mid 2008.

The countries, which have been the top buyers of corn for the past month, have likely built up their inventories to a comfortable level after increasing purchases because of fears about tight supplies, analysts said. Reduced demand could weigh on corn futures, which reached 32-month highs this week at the Chicago Board of Trade.

"Considering that those two have been the big dogs, their leadership role may start to ease out just because of the sheer size of what they've already bought," said John Kleist, senior analyst with ebottrading.com, an agricultural research and brokerage firm.

Strong weekly export sales of 1.2 million tons helped corn futures climb Thursday, with most-active corn for May delivery jumping 2.1% to $7.36 3/4 a bushel. Japan and Mexico accounted for nearly 80% of sales, which covered the week ended Feb. 24.

Japan ramped up purchases recently as it found itself in a "panic situation" due to concerns about rising corn prices and tight supplies. Corn inventories in the U.S., the world's top grain exporter, are projected to come in at a 15-year low at the end of the crop's marketing year on Aug. 31 due to strong demand and a disappointing harvest last fall.

With that in mind, Japan "did what they thought was the prudent thing, saying, 'Let's just book it now, disregard the price, and we'll talk to you later,'" Kleist said. He estimated Japan had probably bought enough corn to keep officials comfortable through the spring planting season in the U.S. and into early summer.

"They certainly were nervous or on edge because they weren't comfortable with the amount they had," Kleist said of Japanese buyers.

Mexico increased buying after a freak freeze in early February killed corn in northern areas of the country. Mexican officials last week said replanting would recover a large part of the more than four million tons of corn lost in the freeze, which could help slow purchases from the U.S.

Indeed, a setback in demand wouldn't be surprising, unless the corn market experiences a selloff, Benson Quinn Commodities told clients in a note. Export sales to Mexico for the week ended Feb. 24 were 381,200 tons, down from 676,900 tons a week earlier, while export sales to Japan were 578,900 tons, up from 468,400 tons a week earlier.

"Given their recent pace, one has to believe that they improved coverage considerably," Benson Quinn said.

In other markets, ethanol for May delivery ended up 2.8 cents, or 1.1%, at $2.613 per gallon at the CBOT. Oats for May delivery rose four cents, or 1%, to $3.94 a bushel.