Wealthy centre-right businessman Sebastian Pinera has cast his ballot in the first round of a presidential election in Chile.The conservative billionaire entered the fray with a commanding 10 point lead in the opinion polls. His election would bring an end to two decades of centre-left rule since dictator Augusto Pinochet relinquished power in 1990. His nearest rival, Eduardo Frei is the candidate most likely to force a run-off vote if he can stop Pinera getting 50 per cent of the vote. Analysts say the electorate is disillusioned with the current regime’s failure to spend the proceeds of Chile’s plentiful copper resources on social programmes. Outgoing President Michelle Bachelet has featured prominently in Eduardo Frei’s election campaign. Constitutionally barred from a second straight four-year term she has been unable to transfer her 77 per cent rating to her would-be successor. Frei is reported to have made a pact with the fourth placed presidential candidate to block a Pinera victory if the duel goes to a second round.