Shares of Cognizant Technology Solutions Corp. CTSH, +1.27% tumbled 8.4% in premarket trade Friday, after the consulting company disclosed an internal investigation it whether certain payments it made to facilities in India violated the U.S. Foreign Corrupt Practices Act. Cognizant said it notified the U.S. Department of Justice and the Securities and Exchange Commission of its investigation. Separately, the company said Friday that President Gordon Coburn resigned from the company on Sept. 27. Rajeev Mehta, chief executive of the IT services business, was named president on Sept. 28. The stock had lost 8.4% year to date through Thursday, while the S&P 500 SPX, +1.05% had gained 5.2%.