CHS Inc., the nation's largest farmer-owned cooperative, is getting back into the ethanol-making business, hoping that the third time is the charm.

The co-op based in Inver Grove Heights said Wednesday that it will purchase a large ethanol plant in Rochelle, Ill., and is looking to acquire other plants and globally expand sales of the biofuel and its byproduct animal feed called dried distillers grains.

"We are really looking at this as a first ethanol plant," said Mark Palmquist, who is chief operating officer of CHS' ag business. "We would be looking at other purchases. This is really a start of a strategy."

CHS, which had $44.5 billion in revenue in fiscal 2013, has long marketed ethanol and traded distillers grains as part of its vast global commodities business. CHS also owns two petroleum refineries, blends ethanol with gasoline and sells fuel at 1,400 Cenex-brand stations across the country.

The co-op has twice entered — and exited — the business of making ethanol from corn.

In the 1980s, CHS and Archer Daniels Midland Co. owned a small, first-generation ethanol plant in North Dakota, but CHS sold its stake in 1991. Fifteen years later, in 2006, CHS acquired 24 percent of US BioEnergy, which then owned four ethanol plants. But CHS had to write off $74 million of that investment after US BioEnergy merged with VeraSun and the combined company filed for bankruptcy in 2008.

Palmquist said CHS learned a lesson from its passive investment in US BioEnergy, whose business was not integrated with the Minnesota co-op's commodities-­trading strengths.

"We are a leading trader in DDGs, we are a leading trader in ethanol," Palmquist said in an interview. "We look at it and say, 'This time around this [ethanol plant] is something that should be part of our portfolio of operating companies.' That is why we are taking it on as the full owner of the plant."

Larry Johnson, a Cologne, Minn., ethanol industry consultant, said CHS' re-entry into the ethanol business is a sign of the co-op's confidence in the biofuel industry.

"It shows they have got a high level of optimism in agriculture, ethanol and themselves," he said. "I think it is a good move."

CHS didn't disclose the terms of the acquisition of Illinois River Energy, but said the purchase is a cash deal that is expected to close in June. Palmquist said CHS plans to retain the approximately 60 employees of the plant 80 miles west of Chicago.

The plant was built as a smaller ethanol refinery in 2006, and after a major expansion now produces 133 million gallons of ethanol, along with corn oil and distillers grains.

Sinav Ltd., based in London, has owned the plant since 2012. Sinav is a unit of London-based Harwood Capital and Siem Industries Inc., a diverse company with shipping and oil services segments based in the Cayman Islands. The Illinois operation was Sinav's only ethanol plant.

Richard Ruebe, CEO of Illinois River Energy, said Sinav put the plant up for sale in January and had multiple bidders. He said CHS has marketed the plant's ethanol since 2006.

"We have had a strong relationship with them through the highs and lows," Ruebe said in an interview. "They have been a good business partner."

Palmquist said the Illinois plant is well run and in a good location for corn and transportation. He wouldn't say whether CHS has other pending deals for ethanol plants, but said the company's strategy aims to export ethanol and distillers grains.

"It is becoming more global," he said of the ethanol business, "and that fits our structure."

David Shaffer • 612-673-7090