There was no "bid letting." Public companies are always availble for takeover. P&O was a publicly traded company.
Unless something's changed to make the idea more palatable, I can't see a US firm doing now, not for long anyway.
DPW may create a subsidiary that is wholly US-owned. Same people, different legal and tax structure.
Then why not do that in the first place? I'm just wondering if that would be enough to get around the problems that make the deal less than attractive for American companies.