Alien comes to Earth, builds tele-transporter device but keeps the technology secret. Humans manage to spy on it. The alien 'sells' the device to humans (like Brooklyn Bridge!).
The alien doesn't own the technology, but he signs a legal document selling it anyway. Later in the novel, Earth lawyers negotiate with alien lawyers and win the case, because the alien was a legal official and his signature was binding, for some reason or other!
Any leads would be much appreciated.