BUCHAREST (Reuters) - Romanians will vote for a new president on Sunday with leftist Prime Minister Victor Ponta leading opinion polls, and outgoing centrist President Traian Basescu stepping down after two terms in office since 2004.

No candidate is expected to win an outright majority in the first round of voting. A second round run-off is set for Nov. 16. (ID:nL4N0SQ6SB]

Here are pen portraits of the leading candidates from a field of 14 who have registered for the ballot.

VICTOR PONTA

A former prosecutor and amateur rally driver, Ponta, 42, took office in 2012. He became Europe's youngest prime minister after toppling a centre-right government that enforced painful wage cuts and tax hikes at the height of the financial crisis.

Ponta's Social Democrats have courted voters by restoring some of the pensions and wages for state workers cut under his predecessor. Ponta has slashed some taxes and pledged to hike pensions again next year, and may cut loose an aid deal with the International Monetary Fund (IMF).

Ponta and Basescu are bitter rivals and often feuded over policy. Ponta tried and failed to impeach Basescu in 2012, earning a sharp rebuke from the European Union for undermining the rule of law. During the 2014 campaign, Basescu accused Ponta of being a spy in the 1990s, which Ponta's camp rejected as a political smear.

Ponta has been accused of plagiarizing large parts of his doctoral thesis, a charge he also rejected as politically motivated.

KLAUS IOHANNIS

Klaus Iohannis, 55, is the ethnic German mayor of the Transylvanian city of Sibiu, also known as Hermannstadt. He has pledged to try to unite a fragmented opposition to Ponta's leftist rule and advocates economic reforms.

Observers attribute his fast rise to his managerial skills as mayor since 2000. He won praise for overseeing restoration works of the 12th century medieval city established by German settlers, which was named Europe's Capital of Culture in 2007.

During the campaign, critics have attacked Iohannis for his wealth. He owns six houses.

CALIN TARICEANU

Calin Tariceanu, 62, is a wealthy businessman and former prime minister. In 1990, Tariceanu helped resurrect the Liberal Party, which was banned under Communist rule. He also made money by importing and selling cars by France's Citroen.

Appointed prime minister in 2004, his government oversaw Romania's accession to the EU at the start of 2007 and cut taxes to introduce a flat rate of 16 percent which is still in force.

Tariceanu is an ally of Ponta and also feuded with Basescu in his time as prime minister. He recently formed a centre-right splinter group from the Liberals, known as the Liberal Reforming Party.

ELENA UDREA

Elena Udrea is a centrist opposition lawmaker and a close political ally of Basescu, who backs her for president. Udrea was a tourism and regional development minister in 2008-2012 for the centrist Democrat-Liberal Party.

In January, the 40-year-old lawyer resigned from the centrist opposition PDL party following disagreements with its leadership and joined the People's Movement Party (PMP), another opposition group.

Just days before the 2014 election, a blog posted pictures of her and a top anti-organised crime prosecutor ‎shopping in Paris. Udrea said the pictures were taken nine months ago and leaking them was an attack on her private life designed to coincide with the start of the vote.

MONICA MACOVEI

A former justice minister and human rights lawyer, Monica Macovei has been widely credited with overhauling Romania's judiciary and setting up institutions to fight corruption. These include the Directia Nationala Anticoruptie (DNA), which handled a landmark graft probe against former minister Adrian Nastase.

Macovei, 55, lost her job in a reshuffle in 2007 when a reformist coalition between the Democrat Liberal Party and Tariceanu's Liberals collapsed in bitter feuds.

She was voted the EU's woman of the year in 2008 when she was acting as an anti-corruption adviser for the Former Yugoslav Republic of Macedonia (FYROM).

(Reporting by Radu Marinas; editing by Matthias Williams and Ralph Boulton)