WINDHOEK, Aug 17 - Zimbabwe's refusal to obey rulings by a regional court, which rejected President Robert Mugabe's land reforms in favour of a group of white farmers, looks set to win a pass at a summit on Tuesday.

The tribunal of the Southern African Development Community, whose leaders are meeting here, ruled in 2008 that a group of 78 white farmers could keep their land, saying they had been unfairly targeted because of their race.

Zimbabwe has refused to respect the ruling, even though Harare has signed on to the treaty creating the court, which has no power to enforce its decisions except through decisions of a summit.

"The rule of law in the SADC countries depends on this," said Kallie Kriel of the South African rights group AfriForum, a mainly white organisation.

"If the rulings of SADC institutions are not adhered to, the credibility of SADC itself is at risk."

About 4,000 white farmers have been forced off their land in a violent and politically charged campaign launched by Mugabe in 2000.

Around 400 white farmers remain in Zimbabwe, and the chaotic resettlement process slashed food production, making the nation chronically dependent on foreign handouts.

Zimbabwe insists that the SADC tribunal treaty was never ratified. Critics contend that the signature on the protocol was enough. The leaders are expected to simply punt the issue to their next summit in 2011.

"To find a solution, SADC asked its justice ministers to make a report, but it wasn't completed. Any decision will simply be postponed indefinitely," said one official at the summit, speaking on condition of anonymity.

The report was meant to be presented at the summit, but regional leaders fear the contentious issue could split the bloc, which has struggled to act with a united voice on Zimbabwe, even at the height of electoral violence in 2008.

So far only South African courts have registered the judgement, leading to the seizure of Zimbabwe government properties for auction to help cover the farmers' legal costs.

"There is no possibility of punitive measures like sanctions," said Dirk Kotze, a political analyst from the University of South Africa.

"Expressing their disappointment is the furthest they can go," he said. "Anything further would be punitive and it has to be weighed against other political considerations such as maintaining unity in the government."

Mugabe, who at 86 is Africa's oldest leader with three decades in power, formed a unity government last year with former opposition leader Morgan Tsvangirai, now the prime minister.

South African President Jacob Zuma, the regional mediator in Zimbabwe, was to brief the summit behind closed doors on the power-sharing pact late Monday.

His foreign ministry said he would present an overall optimistic picture, praising Zimbabwe for stabilising its economy while voicing concern about relentless feuding within the government.

The political bickering has delayed progress on election reforms. The power-sharing pact had called for a referendum on a new constitution for last month, but the process has barely gotten off the ground.

SADC has been much tougher on Madagascar, which was suspended from the bloc over the army-backed ouster of president Marc Ravalomanana by the former mayor of the capital Andry Rajoelina in March 2009.

The leaders were also expected to be briefed on a new agreement signed last week between Rajoelina and 99 political parties, including Ravalomanana's, setting out a new election calendar.