Partial returns in Finland's presidential election show opposition leader and former prime minister Esko Aho ahead in the poll.

Mr Aho is leading with 38.6% of the vote, followed closely by Social Democrat Foreign Minister Tarja Halonen with 37.5%.

Reports say the result indicates that the pair will face each other in a run-off vote on 6 February.

If elected, Ms Halonen would become Finland's first female head of state.

The partial result is based on about one-third of the votes, cast in advance balloting, although the final outcome could still change significantly.

Finns turned out in high numbers to vote despite snowstorms, sleet and rain. However one-third of the country's 4.2 million voters had already cast their ballots in advance at post offices.

Results were expected within several hours of the polls closing at 2000 (1800 GMT).

Shared opinion

Correspondents say the election has become a battle of personalities rather than policies.

Not only do the leading contenders agree on the big issues, changes in the constitution have curtailed the president's role as the sole leader of the foreign and security policy.

They share an approval of membership in the European Union, which Finland joined in 1995, and plan to continue the country's post-World War II policy of neutrality.

But while Ms Halonen openly refuses to marry her long-term boyfriend, Mr Aho - a suave politician dubbed the "Kennedy of Finland" - has made a point of including his family in his campaign appearances.

Colourful candidates

Another presidential hopeful, the flamboyant Parliament Speaker Riitta Uosukainen, has candidly described making love on a waterbed.

Although she led the field in earlier surveys, her support base has since dropped away.

Other candidates include the former UN peace envoy, Elisabeth Rehn; Risto Kuisma, a former hard-drinking union boss who is now a leading member of the temperance movement; historian Ilkka Hakalehto; and Green Party member Heidi Hautala, who sits in the European Parliament.

President Martti Ahtisaari, 62, is not seeking a second term after six years in office.

If none of the seven candidates reach the required 50% threshold in the first round, a run-off between the two leading candidates will take place.