Home Media Research reports Blu-ray is outselling HD DVD by 2-to-1 in the U.S. in the first half of 2007.
The division of Home Media Magazine said total sales of Blu-ray discs, using a Sony-backed technology, totaled 1.6 million units from January 1 through July 1, compared with 795,000 HD-DVD discs sold in that period.
HD-DVD was developed by Toshiba and backed by Microsoft and film studios such as Warner Bros.
Both formats were launched in spring 2006. An estimated 3.7 million high-definition discs have been sold, including 2.2 million in Blu-ray and 1.5 million in HD-DVD through the end of July, according to Home Media.
A Home Media spokeswoman said Blu-ray got a further boost in August from strong sales of the 300 title. Stephen Nickerson, senior vice president, market management at Warner Home Video, reported sales of about 190,000 Blu-ray units of the film, versus 97,000 in HD-DVD since July 31.