CBOT grain traders got their first taste on Thursday of trading without a two-hour cushion between the release of price-sensitive U.S. government data and markets being open, as the new 21-hour trading cycle exposed some frayed nerves.

The U.S. Department of Agriculture issued its weekly export sales report at 7:30 a.m. Central (1230 GMT) when the Chicago Board of Trade grain markets were open for business. The CBOT began a 21-hour trading cycle on Monday.

Rival Intercontinental Exchange was also open, but its volume was far smaller than that of the world's largest grain exchange, owned by the CME Group.

The data moved the corn futures market, with benchmark July slipping slightly lower in a knee-jerk reaction before rebounding after traders dug deeper into the data to find that there China had bought U.S. corn.

Corn futures fell back later in the session due to the weekly export sales of corn coming in below trade expectations.

"The initial knee-jerk reaction was corn sales weren't good so that weakened corn a little. But later when the full report came out it showed old-crop corn sales switched to China and it showed soybean sales to China," said Jerrod Kitt, analyst for Chicago-based trade house The Linn Group.

"Anytime those kind of numbers show up for China, it gets the trade attention... But it's another example of the little guy getting run over if he isn't able to digest the numbers quickly," Kitt said.

Some of the opposition to the 21-hour trading cycle was pegged to how larger trading companies would have an advantage over smaller ones because they had more people to dissect USDA data and could trade on it sooner.

But there is a push now by options traders to extend the trading hours in the pit to 7:20 a.m. Central so that they could capture some of the business that takes place in the early part of the day, especially on days of USDA reports.

CME executives met with grain traders on Wednesday, and were expected to seek federal approval to extend trading hours for its open-outcry trading session, traders who attended the meeting that was closed to the media said.

"I think there's a case for having the pits open for more than just the monthly WASDE reports," a CBOT floor trader said, referring to the price movement after Thursday's export data was released. The USDA releases its World Agricultural Supply and Demand (WASDE) reports monthly.

"COMPROMISE AND AN EXPERIMENT"

"I believe it is a compromise and an experiment. With summer coming up it will be more volatile so it will be interesting to see how this turns out," said Matt Pierce, analyst and options strategist for GrainAnalyst.com.

"There will be two big tests in June."

On June 12 the USDA will release its updated supply and demand report and in late June the USDA will release updated U.S. crop planting data.

Pierce said "staying open with pit trade until 2:00 p.m. (1900 GMT) would be a relief for options traders, especially during expiration."

"The way it is now with pits closing at 1:15, it leaves options traders hung out to dry during expiration. Currently they would have to peg their risk at the target price at the 1:15 close."

Traders said the CME debate centers on whether to open pit trading earlier and close later, open early and close at the current 1:15 p.m. closing time or open early only on USDA report days.

"I could care less about expanded pit trading, but I care about the stock price. I'm trading about 80 percent electronically now anyway, I can trade anywhere," said veteran local trader Alan Caskey.

"I'm an old relic, but I see what the future is."