I am not a copyright expert but what you're saying sounds unlikely.
It is more likely that Parlaphone owned the copyright and not the Beatles, they had a contract with the Beatles which only lasted 25 years. After which, as I said, the copyright owners SOLD them. The Beatles could have been offered them first as you say and declined but the result is the same, they were SOLD by the owners.
Probably a very simplified view but AFAIK music copyrights (at least in the UK) last by default for 50 years. After which they become public domain and can be published free by anyone.
Something that Cliff Richards tried to change (extend) and failed.
Last edited by alexh; 18 October 2009 at 23:00.