International Speedway Corporation or ISC is a corporation whose primary business is the ownership and management of NASCAR race tracks. About 55% of the stock in ISC is owned by the heirs of NASCAR founder William France Sr. and the remainder trades on the stock market. Although ISC is majority-owned by the France family, it is separate from NASCAR. In 2005, Kentucky Speedway filed a lawsuit against ISC and NASCAR, claiming that NASCAR violated federal antitrust laws by not awarding them a Sprint Cup race, noting the close relationship between NASCAR, ISC, and the France Family.