Sony and Pioneer have pushed back the release dates of their much-anticipated Blu-Ray players.

Sony's BDP-S1 has an estimated ship date of 15 August, with an expected price tag of $1000.

This means that it is scheduled to launch almost 4 months later than expected.

Pioneer's player will emerge after Sony's, in September, and now has an estimated price of $1500, which is $300 less than originally announced.

News of the delay has been greeted by speculation that the development of the format is not quite going to plan in the build-up to Sony's PS3. The company announced that the PS3 would support Blu-ray in August 2004.

It's widely recognised that the adoption of DVD technology in the PS2 kick-started the spread of that format, so it's hoped that Sony can do the same for Blu-ray, which is the rival format to HD-DVD.

At the moment, Sony is promoting the BDP-S1 Blu-ray Disc Player by bundling it with copy of "The Fifth Element".