Costa Ricans went to the polls on Sunday to elect a new president from 25 candidates, with no clear favorite for addressing growing economic concerns in one of Latin America's most stable democracies.

Polls indicate about a third of the country's 3.5 million voters are undecided as they are faced with a choice from more than a dozen candidates.

Unemployment, corruption and living costs are among the top concerns for the electorate and a worsening economic situation has hit confidence in the political class.

The economy has stalled under President Carlos Alvarado Quesada, while the Citizen's Action Party (PAC) candidate, former economy minister Welmer Ramos, appears to be paying the price for the high anti-government feeling, with only 0.3 percent of people expressing support.

It means the country's traditional political heavyweights -- the centrist National Liberation Party (PLN) and the right-wing Social Christian Unity Party (PUSC) -- could return to the fore after decades of a near political duopoly only recently broken by the PAC.

A candidate requires 40 percent of the vote to win the first round outright; however, a presidential runoff on April 3 is expected.

The national election tribunal is expected to announce the results about three hours after polls close.

(With input from agencies)