The Czech parliament has again failed to elect a president to succeed Vaclav Havel after three rounds of voting.

Lower house speaker Ludomir Zaoralek announced that neither former prime minister Vaclav Klaus nor former ambassador Jaroslava Moserova gained enough votes to win.

A previous three rounds of voting last week also failed to produce a winner.

Klaus: Controversial ex-prime minister

A third election in the legislature is now expected, although only days now remain before Mr Havel's mandate ends.

"The stubbornness of certain people, acting for personal reasons, cut me off," said Mr Klaus, who received the most votes on both occasions.

A third candidate, former Social Democrat prime minister Milos Zeman, was eliminated in the first round on Friday.

Calls for new system

Results from the first two rounds gave Ms Moserova the edge in the upper house while Mr Klaus dominated the lower house.

While the first stages require a majority of votes from each house, the third stage needs a simple majority of all deputies across the board.

Moserova: Surprise success in latest votes

But MPs can choose to spoil their ballots - and so deprive one of the two remaining challengers of the necessary 50%.

Thus Mr Klaus received only 127 votes across the two houses, falling short of the required 141 to win. Ms Moserova received 65 votes.

The BBC's Ray Furlong says the second failure will doubtless add to the calls for the president to be elected by the people in a direct vote.

But a change to the voting system would take time and leave the Czech Republic without a president at a crucial time in its preparations for European Union membership.

Unlikely duel

Any change to a popular vote would likely hand the presidency to Mr Klaus - far and away the leader in opinion polls.

Mr Klaus said after Friday's vote that he would stand in any future election whether it was countrywide or in parliament.

Zeman: Defied expectations with first round failure

Many analysts had predicted a tense dual between Mr Klaus and Mr Zeman in Friday's vote.

Reports suggest that many of Mr Zeman's colleagues have voted against him to avoid giving him a platform to challenge his bitter rival, the current prime minister and fellow Social Democrat, Vladimir Spidla.

Mr Zeman only entered the race after a compromise candidate for the Social Democrats had a miserable showing in last week's vote.

Ms Moserova also entered the contest late, standing with the backing of independent and Freedom Union and some Christian Democrat deputies.

The 73-year-old doctor is a former diplomat and translator of Dick Francis novels.