A Hague based tribunal is scheduled to rule Wednesday on Sudan's disputed oil-rich Abyei border region. This comes after the Khartoum government challenged the Abyei Border Commission's report, contending that it exceeded its mandate.

The tribunal's decision is expected to affect the 2005 Comprehensive Peace Agreement (CPA), which effectively ended the long civil war between the north and South. 

At a recent meeting in Washington, both the government and the Sudan People's Liberation Movement (SPLM) promised to abide by Wednesday's ruling.

Vice President Mark Schneider of the International Crisis Group told VOA that the decision could test Sudan's stability.

"As you know, this is a major decision affecting the CPA, affecting stability in Sudan. And the most recent statements by the government and by the Southern Sudanese have indicated they will accept the outcome of the tribunal. And the anticipation is extremely high within the country," Schneider said.

He said there are indications that both parties will accept Wednesday's ruling.

"One hopes that both sides will accept the outcome and will carry out the steps to implement that outcome in a peaceful and cooperative fashion," he said.

Schneider said the ruling could affect the upcoming referendum.

"The fundamental issue is how the tribunal comes down on the question of the original border decision with Abyei. And if it confirms the original decision, which would essentially provide that most of the resources in that area will fall within southern Sudan, then that makes the upcoming referendum in 2011 extremely important for the future of the country," Schneider said.

He said the ruling could also divide the oil wealth of the Abyei region between the north and the semi-autonomous south.

"The decision could well decide some division of those resources and in a way, that will provide for the sharing of the benefit," he said.

Schneider said a decision by either party refusing to abide by the tribunal's ruling would be regrettable.

"It will be particularly unfortunate for either side to first reject the findings of the tribunal. They both agreed on this independent international arbitration. And most recently here in Washington, they both reaffirmed that they will accept the outcome. And it would be a tragedy for the country if that were not to be the case," Schneider said.

He said there country's peace would not be disturbed if both parties accept the outcome of the ruling.

"The only way forward in a peaceful fashion is in fact for the tribunal's decision to be respected and to be implemented in a rational and objective fashion," he said.

Political observers note the row over the Abyei region became a major flashpoint in the first and second north-south civil war, when the dispute was exacerbated by the discovery of oil.

The sensitivity of the Abyei issue was acknowledged in a special 2005 protocol to the CPA. It stipulated that in five years, when southern Sudan votes on whether to become independent, the residents of Abyei will be able to choose whether they wish to become part of the south or remain in the north. That referendum has been pushed back to March of 2011.