The Commodities Futures Trading Commission called an emergency meeting late last night after a federal judge in Chicago overturned the CFTC's decision to stop trading in March wheat futures.

The latest decision -- unless it is overturned -- will allow the Chicago Board of Trade to resume "March wheat" trading today.

The commission last Friday declared an emergency and stopped the trading, charging that four professional grain speculators had "cornered the market" and could make millions of dollars in windfall profits by driving up the price.

At 11:30 p.m., CFTC officials announced the agency would appeal the decision to the 7th U.S. Circuit Court of Appeals in Chicago. Four appellate judges were to hold a hearing before the wheat market opens at 930 a.m. on a CFTC attempt to stay execution of the order.

In a major confrontation between the federal commodities regulatory agency and the nation's biggest commodities market, the CBOT sued the CFTC in federal court, and after a hearing yesterday afternoon, Judge John F. Grady issued an injunction reversing the CFTC action.

After half a dozen Board of Trade witnesses testified that recent wheat trading had followed normal industry practices, Grady ruled there was no emergency that required trade to be stopped.

The judge's decision directly challenged the emergency powers the CFTC was given when Congress created the agency in 1974.

The CFTC maintains that the four speculators hold more than 80 percent of the "long" or buying positions in the March wheat contracts, and there are not enough supplies to fulfill the outstanding contracts.

Meanwhile, at the New York Mercantile Exchange, where the CFTC is investigating possible irregularities in gold and potato futures trading, Richard Levine has resigned as president.

The Mercantile Exchange about two weeks ago voluntarily suspended trading in Maine potato futures for March delivery, saying there was a shortage of the high quality potatoes the market requires.

The CFTC encouraged the exchange to stop potato trading, saying that the shortage -- whatever its cause -- created the potential for speculators to inflate the price of potatoes artificially.

The CFTC reportedly is investigating the activities of one New York Mercantile Exchange potato trader and one produce dealer who was active in the Maine potato market just before the shortage was reported.