John,
That wouldn't quite work in this situation.
The OLD website is still very much an active functioning site.... its is just one service which has been split into another company. So for example... we only want to redirect;
www.oldwebsite.com/servicename
to the NEW website.
I could of course just edit the old page and say ...."click here to go to the new site"..... but it does wind me up somewhat that the ideal solution, and proper way to do it is a 301.... but if we do it they get put under penalty.
The official Google line about doing what we want to do is a 301 redirect..
http://googlewebmastercentral.blogspot.co.uk/2012/04/how-to-move-your-content-to-new.html
To quote them "It’s important to redirect all users and bots that visit your old content location to the new content location using 301 redirects."
I wonder if a cross-domain canonical would be worth doing?