Shares of Indian Oil Corporation will turn ex-bonus on Thursday. The PSU major is rewarding its shareholders with one bonus share for every share held. Shares will remain active, as investors wishing to receive the bonus shares need to buy them by Wednesday. The bonus impact will reflect in the derivative segment from March 15. The market lot in F&O would be doubled to 3,000 shares from the current 1,500. Options price will also be adjusted to the bonus issue.