Telstra Health, a unit of Australia's largest telecommunications business Telstra Corp, bought 2 per cent of Orion Health Group in the healthcare management software developer's bookbuild last week in the lead up to its listing later this month. The Melbourne-based telecommunications business spent $20 million buying 3.5 million shares at $5.70 a piece in last week's bookbuild, which valued the company at $915 million, Auckland-based Orion said in a statement.