A fearless stuntman walked a tightrope over the world's highest residential building on Wednesday, breaking an Australian record.

Kane Petersen, a little-known daredevil, traversed a 21-meter rope erected between two peaks on Melbourne's Eureka Tower, hovering almost 300 meters above the ground with no safety net.

It took Petersen only minutes to complete the sky-high stunt, but he described the feat as the greatest of his career.

"This is one of the top of the tops," Petersen told Melbourne radio on Friday, adding, "I'm always looking out for the next big thing."

Eureka Tower offers tourists the highest aerial view of any building in the city at 297.3 meters.

The tower's manager John Forman said Petersen had made an astronomical jump in height to break his previous personal best.

"His biggest high-wire act has been 60 metres, whereas this is 300 metres," Forman said.

In 1974, thrill-seeking tightrope artist Philippe Petit conducted a daring 471-meter walk between the United States' now fallen World Trade Centre buildings.

Petit's record for the highest tightrope walk ever completed stood until last year, when Swiss aerialist Freddy Nock traversed a gap between two mountains 3,532 meters above sea level.