The latest delay is reportedly down to Apple Corp - which houses the group's back catalogue - and copyright holder EMI failing to agree terms to release the tracks on iTunes and other download services.
McCartney said: "That is constantly being talked of - we'd like to do it. What happens is, when something's as big as the Beatles, it's heavy negotiations.
"We are very for it; we've been pushing it. But there are a couple of sticking points, I understand. So the last word I got back was that it had stalled, the whole process.
"[EMI executives] want something we're not prepared to give them. Hey, sounds like the music business.
"It's between EMI and the Beatles - what else is new."