Ethical and honest corporations can increase their stock value by buying back stock on the open market.
Dishonest, corrupt and unethical corporations, like ConAgra under Sean CONnolly,, do it by forcing their loyal employees to sell back their CRISP ConAgra stock to the company.
This allows the SLT to exercise their stock options now or at a future day to gain more control of the company and reduce to an insignificant level any employee ownership.
In other words to once again screw the employrees, make piles of cash and get the company ready to sell.