Regional viewers will lose high-definition channel 9HD and the lifestyle channel 9Life when Southern Cross Austereo switches to showing the Nine suite of channels from Friday July 1.

The regional broadcaster says it won't be able to upgrade its transmission equipment in time for viewers to be able to watch the third rugby league State of Origin match in high definition.

Live TV coverage of the third rugby league State of Origin match won't be available in HD in regional markets. Credit:Getty Images

At the end of the month Southern Cross Austereo will drop its "Southern Cross Ten" branding and begin carrying Nine's name and programs as rival WIN Network swaps to showing Network Ten content.