Say I am a malicious CEO of
Company A which has patented one of our products. At a later point in time, I then publicly give verbal permission to
Company B to produce this product. (Permission is not given over any other avenue of communication)
Company B has made a fortune off of our product, would I be on good grounds for infringement? Does it change if I have given them written permission but not filled out a licensing agreement?
In short, can I use anything besides a licensing agreement to give permission to produce a patented product?
If the answer is different from country to country, then assume we are talking about US law.