Not reducing A/S, reducing O/S Outstanding and putting the 100 million into what is known as Treasury Stock, but the CEO at his discretion can retire or resell Treasury Stock.
What is Treasury Stock (Treasury Shares) Treasury stock is outstanding stock repurchased from stockholders by the issuing company. These shares are issued but not outstanding and are not included in the calculation of dividends or earnings per share (EPS). Treasury Shares vs. Retired Shares Treasury stock can be retired or held for resale in the open market https://www.investopedia.com/terms/t/treasurystock.asp