Oil futures prices advanced beyond the $19 barrier for the first time since early January, but then backed off to close lower Wednesday on the New York Mercantile Exchange.
On other markets, livestock and meat were higher, corn was lower but most wheat and soybean futures were higher and precious metals were mixed.
West Texas Intermediate crude oil extended its recent runup to $19.08 a barrel before surrendering the gains.
"Oil took a little breather," said Richard Marose, an analyst in Chicago with Stotler & Co.
When shipping charges are taken into consideration, he said, a price of $19 a barrel or a little above roughly equates to $18 for OPEC oil.
The Organization of Petroleum Exporting Countries has been limiting production to keep prices in the $18 range.
"The market really cannot understand going too much above $19," Marose said. While the general tenor of the news coming to the market is bullish, with OPEC holding to its production agreement, this isn't enough to propel prices much beyond $19 on the New York Mercantile Exchange, he added.