Eidos will release Tomb Raider Anniversary for Xbox 360 via the Live Markeplace this autumn - the first time a full retail game has been rolled out via downloads.
The title will be avalable in four episodes; the first two will be released with a training mission in September, with the next two arriving shortly afterwards. A full retail version won't be released until later in the year.
"We have created this version of Anniversary specifically for digital distribution as episodic content," said SCi's chief executive Jane Cavanagh.
"This is part of our strategy to grow our presence in online and digital distribution as we believe there are huge growth opportunities arising from this delivery format and we intend to capitalise on the increasing demand for digitally downloaded content."
Microsoft's general manager of third party publisher George Peckham added: "We're continuing to break new ground in getting incredible gaming experiences in the hands of consumers. We're excited to be able to deliver one of the most well-recognised franchises in video game history with Lara Croft Tomb Raider Anniversary to our more than six million Xboox Live members worldwide in the form of episodic content."
Eidos continues to drive activity in new media and emerging games markets - it started a new casual games division last month and continues to drive activity in its mobile games division.