Kirchner claims Argentine victory
Cristina Fernandez de Kirchner has claimed victory in Argentina's presidential elections.
Her claim comes after early official results, based on 15% of ballots being counted, gave her 42% of the vote.
The count backs up earlier exit polls and such a margin would be enough to elect her without a run-off poll.
If confirmed by the full count, she will succeed her husband Nestor Kirchner and become Argentina's first elected female president.
"We've won by a wide margin," she told supporters in a speech at her campaign headquarters at a hotel in Buenos Aires.
27m eligible voters
14 candidates running for president
Winner needs 45%, or 40% plus 10-point lead
If needed, second round on 25 November
New president to be sworn in on 10 December
As her husband, the outgoing president, stood at her side, she said she would build on his work.
"We have repositioned the country, fought poverty and unemployment, all these tragedies that have hit Argentines," she said, referring to the country's recovery from the 2001 economic crash.
The early count put her nearest rivals as Mr Kirchner's ex-Economy Minister Roberto Lavagna with 21% and former beauty queen Elisa Carrio with 18%.
If Mrs Kirchner takes more than 45% of the full vote, or 40% with a 10 point lead over the next nearest candidate, she will win the presidency without facing a second round of voting.
Mr Kirchner has governed for the past four years, but surprised the nation by deciding not to seek a fresh term.
Polling was extended by one hour in some parts of the country to 1900 local time (2200 GMT) to accommodate a late rush of voters.
Besides a new president, voters were choosing eight provincial governors, a third of the Senate and about half of the Chamber of Deputies.
Some 27 million people were eligible to vote.
Economy and crime
The economy and rising crime have been the two main issues in campaigning.
Mr Kirchner has overseen a return to stability and some prosperity since the economy collapsed six years ago, plunging thousands into poverty, the BBC's Daniel Schweimler reports from Buenos Aires.
But there are fears over how strong the economy really is and general scepticism over official statistics suggesting inflation is under control.
Ms Carrio, the candidate of the centre-left Civic Coalition, is running on an anti-corruption platform and has promised to reduce economic inequality.
She urged the poorest to vote for her in order to take the election to a second round on 25 November.
The other 12 candidates include Mr Lavagna of the centrist Coalition for an Advanced Nation and a well-known free-market economist, Ricardo Lopez Murphy.
Mrs Kirchner's critics have attacked her for failing to outline exactly what her policies are, but voters who spoke to the BBC's Will Grant in Buenos Aires said the opposition had failed to offer any real alternative.
Just a few months ago, Mr Kirchner was riding high in the opinion polls and looked set to continue for a second term.
However, it was announced in July that his wife Cristina, senator for Buenos Aires province, would stand in his place. No explanation was given.
As candidate for the governing Front for Victory, she has promised to continue her husband's centre-left policies.
As well as facing comparisons with Eva Peron, Argentina's legendary former first lady, Mrs Kirchner has been compared to former US First Lady Hillary Clinton, who is also a lawyer and senator seeking to become the first elected female president of her country.
"I don't want to be compared with Hillary Clinton or with Evita Peron, or with anybody," she said recently.
"There's nothing better than being yourself."