Seven times Tour de France champion Lance Armstrong will launch his comeback in South Australia's Tour Down Under in January, officials said Wednesday.

The move was announced by state Premier Mike Rann, who said Armstrong's participation would make the tour "the biggest sporting event in South Australian history."

The 37-year-old cancer survivor rocked the world of cycling earlier this month by confirming that he was planning a comeback with the goal of winning a record eighth Tour de France next summer.

"What Lance wants to do is to use his comeback to really globalise his campaign to raise awareness and also raise funding for research into cancer prevention and cancer treatment," said Rann.

"We will be very willing partners in that."

Armstrong was expected to reveal more information later Wednesday, at noon New York time (1600 GMT).

"This guy is bigger than cycling in terms of what he has done," said Tour Down Under race director Mike Turtur.

"In terms of athletes, he's a superstar of sport throughout the world. This is, to me, the biggest thing that has happened in sport in South Australia. He will have a massive pulling power."

Turtur said the Australian race would be "a great way for him to start his preparation" for the Tour de France.

"There is enough in this race in terms of difficulty to really be right up his alley," he said.

The six days of competitive racing from January 20-25 will see riders cover more than 800 kilometres (50 miles) across South Australia.