Monsanto Co. is suing rival Aventis CropScience over Aventis' patents for genetically engineered cotton. Aventis CropScience is a unit of Aventis SA, one of the world's largest makers of farm chemicals. The lawsuit, filed last week in U.S. District Court in St. Louis, is the latest twist in a battle between the two companies over the market for biotech cottonseed. Last March, Aventis sued Monsanto in federal court in Lubbock, Texas, over St. Louis-based Monsanto's patents for genetically engineered cotton. Aventis also has been claiming that Monsanto's development work with the Bollgard II gene infringes its own patents relating to cottonseed, according to the lawsuit. Monsanto asks that a judge resolve the conflict by declaring that Aventis' patents are invalid and unenforceable. Aventis officials weren't immediately available for comment.

** NOTICE: In accordance with Title 17 U.S.C. Section 107, this material is distributed for research and educational purposes only. **