Sports and film channels are thought to be the first to be broadcast in HD.
Sony will be responsible for constructing a new HDTV studio at the satellite giant's Isleworth headquarters and provide training to BSkyB staff during its transition to HDTV.
Tandberg Television will provide the video encoding and distribution system while the delivery of programming in both high- and standard-definition formats will be provided by a tapeless ingest and playout system developed by The Harris Corporation.
Last month Thomson was named as the initial manufacturer of its HDTV digiboxes.
"The launch of HDTV is the most significant development for BSkyB's broadcast infrastructure since the launch of Sky digital in 1998," said Alun Webber, BSkyB's group director of engineering and platform technology. "These supplier contracts keep us on track to launch HDTV in 2006."
HDTV offers a step change in picture quality, delivering a home viewing experience similar to that offered in cinemas. Pictures are delivered in widescreen format.