Bronislaw Komorowski, the candidate of Poland's ruling pro-business Civic Platform has won the presidential election run-off, removing a potential obstacle to reforms needed to repair battered public finances.

An exit poll by TVP state television gave Mr Komorowski, who was previously acting president, 53% of the vote against 47% for his rival Jaroslaw Kaczynski, leader of the right-wing main opposition party Law and Justice.

Mr Kaczynski, the identical twin brother of President Lech Kaczynski whose death in a plane crash in April precipitated the election, quickly conceded defeat.

Investors will welcome the result because Mr Komorowski and Prime Minister Donald Tusk are close allies from the same party, and the new president is expected to work smoothly with the market-oriented government.

Mr Komorowski, who as speaker of parliament became acting president on Lech Kaczynski's death, struck a typically conciliatory tone in claiming victory.

‘Today democracy has won, our Polish democracy, he told jubilant spporters.

‘It is important not to foment divisions but to build a sense of unity.’

Investors had feared a Kaczynski win because of his opposition to spending cuts and privatisation and the likelihood of increased conflict between government and president.

In Poland, the government led by the prime minister sets policy, but the president can propose and veto laws, appoints many key officials and has a say in foreign and security policy.

The election turnout was relatively high at 56.2%, up from 54% in the first round two weeks ago.