SEOUL: Park Geun-Hye, the daughter of an assassinated dictator, officially launched her bid Tuesday to become South Korea's first female president, with polls placing her as frontrunner in December's election.

The veteran politician, who is expected to secure the ruling conservative New Frontier Party's nomination at its primary next month, softened her message in a speech apparently intended to broaden her appeal beyond conservatives.

Pledging to work for a fair and transparent market economy, Park, 60, vowed to expand welfare and push for "economic democratisation" amid a widening wealth gap and high youth unemployment in Asia's fourth largest economy.

"Our economy has excessively emphasised efficiency and disregarded the importance of fairness, resulting in an increased income gap and imbalances," she told cheering supporters at a shopping plaza in western Seoul.

"I will... create a government that boldly and resolutely enforces laws to make influential companies fulfill their social responsibilities," she said.

Huge conglomerates fostered by her father Park Chung-Hee in the 1960s and 1970s still dominate the economy, sparking resentment at their omnipresence.

About 1,000 supporters -- mostly middle-aged or older and clad in the party's trademark red -- chanted her name and waved national flags, balloons and banners reading "The nation loves you".

South Korea is at a "crucial juncture" faced with an ageing society, a low birthrate and jobless woes for youth, she said, promising to increase investment in the service sectors and in science and technology to help create jobs.

"I will devote my everything to make the Republic of Korea (South Korea) a country in which everybody can achieve their dreams," she said.

Park's father seized power in a coup in 1961 and ruled until his assassination in 1979 by his spy chief. Her mother was shot dead by a pro-North Korean assassin in 1974.

She said Tuesday the death of her parents caused her "unbearable pain" at an young age and called the nation "my mother, my family".

Park narrowly lost the conservative party's nomination to Lee Myung-Bak in 2007. He went on to become president but is constitutionally barred from standing again.

Recent opinion polls show Park beating potential presidential rivals by a wide margin in the December 19 poll.

A Realmeter survey published last week gave her 42.4 percent, followed by 19.6 percent for left-leaning software mogul Ahn Cheol-Soo who has not officially declared his candidacy.

Moon Jae-In, the likely candidate of the main left-leaning opposition Democratic United Party, got 15 percent support.

Park also vowed to ease relations with North Korea that have been icy for years under President Lee, and to work harder to curb Pyongyang's nuclear ambitions.

"It has been some 20 years since the Cold War was over, but the Koreas have still been unable to build a very basic level of trust," she said, vowing to end "the vicious cycle of distrust, confrontation and uncertainty".

She promised to create conditions "allowing the North to become a responsible member of the international community... and will strengthen efforts to make progress in the North's nuclear issue". AGENCIES