iTalk Inc. (fka TALK)

[1manband]

What is stopping UMS from buying the shares on the open market, then retiring them after the merger?

The law. They would have to report such a position to the SEC as soon as they owned over 5% of TALK. But since they haven't, they don't.

http://www.sec.gov/answers/sched13.htm

And buying TALK stock before the merger makes zero sense. Especially since TALK has a significant amount of convertibles outstanding.