By Gideon Long
BBC News, Santiago
**Chile is preparing for the first round presidential elections with four men vying for the job.**Opinion polls show that the frontrunner is a centre-right billionaire businessman Sebastian Pinera.
But he faces a challenge from three left and centre-left candidates - Eduardo Frei, Marco Enriquez-Ominami and Jorge Arrate.
If no one manages to get 50% of the vote, the leading two candidates will go through to a run-off on 17 January.
The signs are that the country could be about to shift to the right, after 20 years of centre-left rule.
‘Second round’
Mr Pinera owns a television channel, a stake in Chile’s most successful football club, and millions of dollars in investment - he looks certain to win Sunday’s ballot.
The big question is whether he can reach the crucial 50% mark which would secure outright victory and give Chile its first conservative government since 1990, when General Augusto Pinochet finally relinquished power.
If he cannot - and most polls suggest he will not - then the contest will go to a second round in January, in which Mr Pinera would face one of the leftist candidates - most probably Eduardo Frei, who is seeking his second term as president after an absence of 10 years.
Mr Pinera has campaigned on a tough law-and-order ticket which appears to have gone down well with voters.
He has also vowed to use his business know-how to reactivate the economy, promising Chileans an annual growth rate of 6% for the next four years.
This is the second time he’s run for the presidency at the head of a centre-right coalition.
In 2006, he lost to the extremely popular outgoing Socialist president, Michelle Bachelet.
But under the constitution she can’t stand for re-election, and her candidate, Mr Frei, is struggling to emulate her popularity.
The third candidate is Marco Enriquez-Ominami, a 36-year-old independent who has emerged from nowhere and split the centre-left vote.
He says Chile needs a new face and new ideas in the presidential palace, after two decades of the same coalition.
The fourth candidate, and rank outsider, is Jorge Arrate, a veteran Socialist who has the support of Chile’s communist party.
The centre-left has been split by in-fighting, and many Chileans appear to be ready for a change.
If Mr Pinera is successful, it will mark the first time in 51 years that the conservatives have taken power in Chile via the ballot box.