Converting a Contact to Lead Status

Hi,
I have a situation where a current contact with an existing account has moved to a new company (not currently a client). And, as such the existing contact will need to be downgraded to a Lead based on his new company. I realize that we can change eh Contact’s relationship to a new company. However, the contact is still not designated a a lead. Is there a way to revert the individual’s status based on this new scenario?