The U.S. Supreme Court ruled on Monday that an Indiana farmer violated agribusiness company Monsanto Co's patent for a type of soybean.

In a case closely watched by the biotechnology industry, the court agreed unanimously with Monsanto that Vernon Bowman, 75, had performed an end-run around the law when he bought soybean grain typically used for animal feed but planted it instead.

Justice Elena Kagan wrote on behalf of the court that Monsanto's patent protections were not, in legal terminology, "exhausted" when Bowman used the seeds without the company's permission.

She made it clear that the scope of the ruling was limited to Bowman's case and did not apply to other self-replicating products, such as computer software.

The case arose when Bowman sought in 1999 to save money by buying commodity grain from a grain elevator.

The seed was not identified as featuring Monsanto's Roundup Ready technology, which protects seeds from herbicides.

Bowman said the patent did not cover the grain he used as seed because it was "second-generation," not the first-generation sold by seed dealers.

Bowman kept the seed generated from the successful crop and used it the following year. He repeated the pattern until 2007.

Monsanto objected, saying Bowman was growing soybeans that were resistant to Roundup herbicide, meaning he was infringing on its patents.

Kagan wrote that patent exhaustion did not allow a farmer to reproduce patented seeds through planting and harvesting without the patent holder's permission.

"Were the matter otherwise, Monsanto's patent would provide scant benefit," she added.

The case is Bowman v. Monsanto, U.S. Supreme Court, No. 11-796.