US agri-business giant Archer Daniel Midland Co has been ordered by the US Supreme Court to pay damages worth US$24m to Japanese seasonings producer Ajinomoto Co.

On Monday, the Supreme Court upheld a decision issued last October by a federal circuit court, which ruled that Archer Daniel was guilty of patent infringement. The Supreme Court judge ruled that Ajinomoto had submitted enough evidence to confirm its patent is valid.

The dispute has rumbled on since 1995, when Ajinomoto filed a suit alleging that the US firm had infringed on its patent with the mass production of threonine, an amino acid for use in animal feed. Threonine had originally been developed in a Soviet research institute, but Ajinomoto acquired the licence to be its sole producer in the US and Japan in 1982.