Thurston, Inc. Seed Brokerage & Corn Brokerage - Olivia, MN Thurston, Inc. of Olivia, MN is recognized as one of the leading hybrid seed brokerage and corn brokerage firms in the United States. Thurston, Inc. acts as a commissioned agent representing two or mo Thurston, Inc. of Olivia, MN is recognized as one of the leading hybrid seed brokerage and corn brokerage firms in the United States. Thurston, Inc. acts as a commissioned agent representing two or more parties negotiating wholesale and production transactions. We serve seed companies and professional seed producers.