BRUSSELS -- NATO's policy-making council was set to approve on Monday a much reduced security force to protect international peace monitors in Macedonia, once the alliance completes collecting rebel weapons, NATO sources said.

The sources said the council would endorse a force of 350 to 600 men, probably led by Germany, to replace the 4,500-strong task force that has been overseeing the voluntary disarmament of ethnic Albanian guerrillas in the former Yugoslav republic.

That mission is due to end on Wednesday, Reuters said.

The new force would serve for up to nine months, depending on when the revamped Macedonian security forces, due to be reformed and retrained to reflect the country's ethnic make-up, were ready to take full charge, the sources said.

The size of the NATO mission has shrunk from proposals for up to 1,500 men because the allies were reluctant to commit more troops to the Balkans when they might be needed to join U.S.-led military action against suspected "terrorists", they said.

The sources said NATO Secretary General, George Robertson, would probably make a flying visit to Skopje on Tuesday to finalize arrangements for the follow-on force with President, Boris Trajkovski, and press the ethnic Macedonian majority to keep its part of last month's peace deal.

Under the accord signed by Macedonia's four biggest political parties, Parliament is supposed to amend the Constitution and pass legislation, giving the ethnic Albanian minority greater rights.

Three countries -- Germany, France and Italy -- have said they are definitely ready to participate in the new force, the NATO sources said.

Independent experts have said a far larger NATO follow-on force would be required to enable monitors from the European Union and the organization for Security and Cooperation in Europe to escort refugees back to their homes and prevent a de facto partitioning of the country along ethnic lines.