Originally Posted by Karnak

There are some good reasons to buy back a stock. To get rid of unfriendly investors (Icahn, et al), or because you believe the stock is undervalued are two of them.

According to my reps at the time, Delta made stock buy backs part of the effort to make the stock investment grade. Corporations deemed investment grade have access to cheaper interest rates for debt, typically better bond ratings, and the ability to issue shares for equity without causing alarm.