UPDATE 4-First lady the favorite as Argentines vote

(Updates with some polling stations open for extra hour)

By Fiona Ortiz

BUENOS AIRES, Oct 28 (Reuters) - Argentines appeared certain to choose their first elected female president on Sunday, with first lady Cristina Fernandez de Kirchner favored to win by a wide margin over her closest rival, another woman.

Many Argentines credit Fernandez's husband, center-left President Nestor Kirchner, with pulling the country out of a deep 2001-02 economic crisis

Pre-election polls showed Fernandez, a powerful senator, leading 13 rivals and likely to take over from her husband in a highly unusual transfer of power between spouses.

Television channels said electoral authorities decided to keep polling stations in the capital open an extra hour, until 7 p.m. (2200 GMT), due to long lines.

Fernandez backers say the economy's turnaround -- marked by millions of new jobs and moves by Kirchner to raise salaries and pensions -- drove their voting choice.

"There are more jobs now. Things have calmed down. People aren't dying to leave the country," said Sergio Arrigoni, 41, a delivery truck driver recalling the hundreds of thousands of Argentines who fled the country at the height of the crisis.

Fernandez has been Kirchner's top advisor during his four-year presidency. Voters tired of boom-and-bust cycles hope she will sustain the bonanza he has overseen.