Australia's Prime Minister Kevin Rudd on Saturday conceded election defeat to conservative challenger Tony Abbott, with six years of Labor rule coming to an end as he wished his rival well.

"A short time again I telephoned Tony Abbott to concede defeat at this national election," he said at a party function in Brisbane.

"As prime minister of Australia, I wish him well in the high office of prime minister of this country."

With 80 percent of the votes counted, the Australian Electoral Commission showed Abbott's Liberal/National coalition was leading in 88 seats in the House of Representatives, to Labor's 56.

Rudd said Labor had "fought the good fight".

"Tonight is the time to unite as the great Australian nation," he added to a cheering crowd of supporters.

"Because whatever our politics may be we are all first and foremost Australian and the things that unite us are more powerful than the things that divide us, which is why the world marvels at Australia."