According to the Delta website, the Delta – Midwest Airlines partnership “[t]erminates June 7, 2010.”
I haven’t found any press release, or mention of this on the Midwest Airlines website. But naturally there is a thread on Flyertalk.
Midwest partners in addition to Delta were KLM, Frontier (as they’re jointly owned by Republic), and Amtrak.
Delta’s departure, as poor as their award availability is, leaves a real hole. And redeeming on Midwest isn’t great either, the program even still has blackout dates.
In the past the airline has had several frequent flyer relationships, including American, Virgin Atlantic, and Scandinavian. But those days appear gone.
While the program wasn’t all that appealing in the first place to me, I’d probably just credit Midwest miles to Frontier at this point. At least they partner with Airtran!
Any Midwest advocates out there disagree? Hit the comments with your explanation.