By Mark Gregory BBC World Service business reporter

A pledge to curb the power of such firms, known as chaebol, was a key theme in his election campaign.

An early confrontation therefore seems likely with the biggest chaebol of them all, Hyundai, which has been implicated in a scandal over secret cash payments to the government of North Korea ahead of the Sunshine summit of 2000.

The row over the payments has shed new light on what was really going on in the run up to the summit, which had been seen as the previous administration's crowning political achievement, and at the time seemed to signal a new era of political reconciliation between North and South.

Soured

The new president has signalled a more sceptical line in dealings with North Korea, making it hard to see how he can avoid handing out some kind of punishment to Hyundai.

At the weekend, the vice-chairman of another big South Korean company, SK, was arrested in a deepening scandal over illicit dealings on the Seoul stock market.

That could stiffen the new president's resolve to bring wayward business leaders to heel.

The Hyundai scandal has left the Sunshine summit, which once seemed like a political breakthrough, tainted by association with a clandestine business deal.

Behind the scenes

Hyundai has admitted providing Pyongyong with $500m three years ago.

The money bought Hyundai the right to build a tourist leisure complex and a business park in North Korea, and also played a role in securing the North's co-operation for ex-South Korean leader Kim Dae-jung's policy of reconciliation.

Kim Dae-jung has recently admitted the payments were made with his government's knowledge.

In February 2003, the policy of reconciliation led to the opening of the overland border between the two Koreas for the first time since the Korean war ended half a century ago.

Around 100 Hyundai officials and invited guests took the first bus journey from South Korea for a 50-minute journey along a dirt road towards the scenic resort of Mount Kumgang in the North.

The trip was envisaged as the first step towards regular overland tourist trips to Mount Kumgang, or Diamond Mountain, which has been developed as a resort by Hyundai Asan.