First lady Cristina Fernandez de Kirchner has won a presidential vote to become Argentina's first elected woman leader.

She claimed victory in Sunday's election after official results showed her with well over 40 per cent of the vote.

"This is a triumph for all Argentines," Fernandez told cheering supporters at her campaign bunker.

"Instead of putting us in a position of privilege, it gives us bigger responsibilities and greater obligations," she said.

Fernandez will take over from President Nestor Kirchner in December in a rare power handover between democratically elected spouses. The Kirchners are Argentina's undisputed power couple and have been called "the Clintons of the South."

The 54-year-old lawyer is one of her husband's key aides and a longtime senator. Voters weary of Argentina's repeated boom-and-bust cycles said they hope she will deepen the economic course set by her husband.

After a deep economic crisis in 2001-02, South America's second largest economy has expanded at China-style rates since Kirchner came to office four years ago.

Growth has topped 8 per cent a year, driven by strong consumer spending and agricultural exports.

However there are also mounting concerns about high inflation, energy shortages and a growing perception among some Argentines the Kirchners may have accumulated too much power.

© Independent Television News Limited 2007. All rights reserved.