Asuncion - Former Roman Catholic bishop Fernando Lugo thanked his followers for his apparent triumph in Sunday's presidential election in Paraguay.

"Thank you for accompanying us from the start, from that small and humble experience of listening to people. Today we can say that those who are small are also able to win," Lugo told a crowd of supporters in Asuncion.

Both exit polls and preliminary official results put Lugo, 56, ahead in the election.

According to the first official results made public by Paraguayan electoral authorities, based on the count of more than 10 per cent of the votes, the centre-left Lugo obtained close to 39 per cent of the vote, ahead of ruling-party candidate Blanca Ovelar with 33 per cent.

Ovelar's party, the conservative Partido Colorado, has ruled Paraguay for 61 years, including the more than 30-year dictatorship of Alfredo Stroessner.

Results gave former military coup leader Lino Oviedo 21 per cent of the vote.

According to exit polls issued earlier by the daily ABC Digital, Lugo was set to obtain around 43 per cent of the vote to Ovelar's 37 per cent and Oviedo's 16 per cent.

The electoral commission reported high turnout, which observers had said was likely to favour Lugo.

According to Paraguayan election law, a plurality is enough for the winner of Sunday's election to succeed outgoing President Nicanor Duarte Frutos, with a five-year mandate.

"That is the Paraguay that I dream of, with many colours, with many faces, everybody's Paraguay," Lugo said.

The former bishop's cheerful supporters went into the streets to celebrate his likely historic victory, but no violence was reported. (dpa)