I am an American citizen living in Canada. I just finished an exchange program at the University of Chicoutimi and I am searching for a job.
My question is the following:
If I find a job and an employer who fills out all my work permit papers and requirements, and my work permit is accepted, what happens if for example the company closes, or my post is cut and I am obliged to leave the company. If this situation happens, am I supposed to find a new job and start the work permit application process all over again, or can I continue using the old work permit that was issued by my old employer?
If I can't reuse my old work permit, is there a type of work permit that exists that can be used to apply for different jobs? What are the options?

Certain Youth Programs such via SWAP or BUNAC may allow for open work permits. As a general rule, otherwise, your work permit will be specific to a position of employment and an employer. If the position is termination prior to expiration of the permit, you are allowed to remain in Canada, but could not work in a new position until a new work permit is granted.