YouTube is on the verge of announcing a deal with three major movie studios to carry their titles for online rentals.

The deal, first reported by movie business site TheWrap, builds on existing rentals of lesser known independent films. Starting from the next week or so, there’ll be content available from Sony, Warner Brothers and Universal, three of the “big six” Hollywood studios. At the moment Disney, Fox and Paramount aren’t signed up, and it seems Google decided not to wait for a clean sweep before going ahead,

In what was presumably a test, YouTube briefly had links to some Hollywood titles on its main store page today, which is currently still viewable on Google’s cached copy.

While users outside the US are blocked from the rentals, some American users report they have been able to rent some of the movies via the cached link, albeit only in low quality versions.

It’s notable that most of the titles on the page are a few years old, though that may not necessarily be indicative of the range that will actually be available. Perhaps more significantly many of the movies listed on the page are priced at just two dollars, which would undercut Apple’s iTunes store, as well as making it more feasible for semi-regular viewers to go for YouTube’s pay-per-view offering rather than pay a monthly Netflix charge.

While the short term talking point about the YouTube launch will be the Google vs Apple vs Netflix battle, it could be net neutrality that is the most important long-term consequence of the move. There have already been rumblings about the staggering amount of data use that’s attributable to Netflix in North America. If YouTube’s movie rentals take off to a similar degree, internet carriers may start arguing that Google should contribute towards the cost of carrying the additional traffic. That’s got the makings of a messy legal argument, particularly given that Google itself has already tried to cosy up to Verizon and make their own proposals for how net neutrality should be enforced.