In a move aimed at encouraging consumers to buy next-generation DVDs, Warner Bros. has unveiled a disc that combines two rival high-definition formats.

On Wednesday at the International Consumer Electronics Show in Las Vegas, Warner introduced its Total Hi Def disc, which plays the HD DVD format on one side and the Blu-ray Disc format on the other,

The HD format battle, reminiscent of the VCR battle between the competing VHS and Betamax systems, has made many consumers wary of buying HD players.

Sony leads a consortium of consumer electronics companies and Hollywood studios that support the Blu-ray format. The consortium includes Dell and Koninklijke Philips Electronics, as well as The Walt Disney Co. and Twentieth Century Fox Film.

In the HD DVD corner is Toshiba, with backing from Hewlett-Packard, Microsoft, and Paramount Home Entertainment.

Warner, which has its foot in both camps, expects Total Hi Def discs to be available in the second half of 2007.

The physical structure of the disc is 1.2 millimeters, the same as that of DVDs, HD DVDs and Blu-ray Discs.

The Total Hi Def disc is able to contain both single layer and dual layers for both formats, enabling either 15GB or 30GB on the HD DVD side and 25GB or 50GB on the Blu-ray side.