Mr Savisaar's party won the most votes
Estonia's general election has ended in deadlock, with two opposing parties winning the same number of seats in parliament.
The left-leaning Centre Party, led by formerly disgraced ex-minister Edgar Savisaar, won the most votes, gaining 25.4% of Sunday's poll, according to provisional results.
That translates into 28 seats in the 101-member parliament - exactly the same as newly-formed conservative group Res Publica, who won fractionally fewer votes.
Estonians therefore have to wait and see who will lead their next government, one which is expected to take the once communist Baltic state into both Nato and the European Union.
Nonetheless, the election cements a remarkable comeback for Mr Savisaar.
He resigned as interior minister in disgrace in 1995 after allegations he had made secret tape recordings of his political rivals.
For the past year, his Centre Party has formed part of the current coalition government under Prime Minister Siim Kallas, of the right-of-centre Reform Party.
The Reform Party limped into third place in the election, with 17.7% of the votes and 19 seats.
The horse-trading will now begin for a new coalition, and Mr Savisaar may yet find himself shut out of government, correspondents say.
Overall, centre-right parties won 60 seats in parliament, with left-oriented parties winning just 41.
Res Publica, which was formed only a year ago, has already ruled out an alliance with Mr Savisaar.
"The only party with which we are not prepared to enter coalition talks is the Centre Party," Res Publica leader Juhan Parts said on Estonian television.
Res Publica campaigned on an anti-crime, anti-corruption platform, and was one the harshest critics of the controversial Mr Savisaar.
However all parties agree on Estonia's pro-West orientation, its drive to join the
EU and Nato.
Estonia - along with Baltic neighbours Latvia and Lithuania - is due to join both organizations in 2004.
President Arnold Ruutel has two weeks to nominate a prime minister, who would then have to present a cabinet to parliament for approval.