2 companies apply for two C.OE.s?

[Aoihime]

Hi, guys i'm a little confused as to what to do and need some advice. I was offered a job position (currently in the U.S.) for an alt company just a few days ago, I also interviewed at Interac on the same day i received the offer from the previous. Now, Interac is suppose to notify me on whether i was accepted within a week. How long can i delay accepting or rejecting the offer from the first since i have yet to hear from interac? I need to send the dispatch alt company an application package, while Interac already has the necessary documents. Is it possible for both companies to go ahead an apply for the coe, and then backing out of one and using the other to obtain a visa?