Ethanol producer Aventine Renewable Energy Holdings Inc. filed for Chapter 11 bankruptcy protection on Wednesday, the latest victim in an industry stung by volatile commodity prices and shrinking profit margins.

It has three Nebraska companies among its 30 largest unsecured creditors, including the Aurora Co-Op Elevator Co., listed in the bankruptcy petition as owed $1,073,051.89.

Aventine, of Pekin, Ill., warned last month that it may have to file if it could not raise sufficient cash.

In its Delaware court filing, Aventine listed assets of $799 million with $491 million in debt.

Aventine's holdings include Nebraska Energy, which has an ethanol plant operating near Aurora, and another under construction near Aurora under the Aventine name. Construction on that plant was suspended last fall.

The Aurora Cooperative has sold its interests in both plants back to Aventine.

But it's listed as Aventine's sixth biggest unsecured creditors.

The co-op said in a statement Wednesday that it continues to be in communication with both Aventine and the bankruptcy court in Delaware.

"We anticipate the continued operation of the Nebraska Energy LLC ethanol production plant," said Aurora Co-op President and CEO George Hohwieler. "We also anticipate supplying corn to that plant and marketing co-products from that plant, assuming we receive adequate assurances within the bankruptcy proceedings.

"The work we accomplished over the past three years has put us in a positive position in our relationship with Aventine," Hohwieler added.

The Aurora Cooperative's overall financial position is not affected by Aventine's Chapter 11 bankruptcy filing, the co-op said.

Other Nebraska creditors listed are Engineering Automation & Design Inc. of Omaha, owed $138,239; and Husker Ag LLC, another ethanol plant, owed $117,551.

Aventine Chief Executive Ron Miller said the company is challenged by a difficult market environment, and the filing will allow it to operate without interruption.

"We will use the Chapter 11 process to more rapidly restructure our overhead, pursue potential investors, and definitively resolve our debt issues," Miller said in a statement.

Aventine last month said it did not expect to have enough cash to satisfy a $15 million interest payment due April 1 nor to pay $24.4 million due to its engineering and construction contractor, Kiewit Energy Co.

In its most recent earnings statement, Aventine reported a fourth-quarter 2008 loss of $36.9 million, 86 cents per share, compared with a profit of $3.3 million, 8 cents per share, a year earlier.

The New York Stock Exchange suspended trading of Aventine shares on March 30, moving the stock to ithe "pink sheets."

Energy analyst and trader Stephen SchorkSchork said net fuel ethanol production fell for a second-straight month in January as poor margins discouraged output.

The nation's renewable fuel standard ensures demand for ethanol by calling for 11.1 billion gallons of renewable fuel to be blended into gasoline this year, with that number climbing to 36 billion gallons by 2022.

"We are taking steps to ensure our business will be ready when the current markets turn up again," Miller said.

The Associated Press and Journal Star reporter Richard Piersol contributed to this report.

Other ethanol bankruptcies

Sioux Falls-based VeraSun Energy Corp., the nation's No. 2 ethanol producer, filed for Chapter 11 bankruptcy protection Oct. 31.

Valero Energy Corp., the nation's largest independent oil refiner, bought five VeraSun plants and is in the process of closing on two more, including one in Albion, for a total $477 million. Secured lenders submitted successful credit bids for the remaining VeraSun facilities, including two plants in Ord and Central Cityi.

Another biorefiner, Pacific Ethanol Inc., warned in a Securities and Exchange Commission filing late last month that bankruptcy protection was a possibility and it may not be able to continue past April 30 without renegotiating its debts or finding new sources of cash.