Apple plans to use the same price system as its standard movie titles for rent and purchase. New titles will cost $19.95 (£13.75) for HD purchase, while rentals will cost $4.95 (£3.40).
The move reflects the increasing amount of bandwidth available to consumers, and the push by media companies to legitimise the new format.
The company said that it is targeting the HD films at standard Mac and PC users, as well as customers who use the Apple TV device with HDTV sets.
"Movie fans are going to love being able to buy and rent films including Quantum of Solace and Twilight in stunning HD from the iTunes Store," said Apple internet services vice president Eddy Cue.
"Customers have made HD content on iTunes a hit, with over 50 per cent of TV programming being purchased in HD when available."
Currently, the company is offering 12 films as HD downloads, including W, Transporter 3 and Punisher: War Zone.
From 21 March users will be able to download Twilight in HD. Three days later, Apple plans to release Quantum of Solace as an HD title as well. Users can pre-order both films.
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