The head of the so-called troika, a team of inspectors from Greece's foreign creditors -- the International Monetary Fund, the European Commission and the European Central Bank -- on Tuesday interrupted negotiations with the government over a package of austerity measures, saying that he had to brief IMF Managing Director Christine Lagarde on the progress of the talks.

Poul Thomsen, deputy director of the IMF's European Department and head of the troika team of inspectors, was meeting with Labor Minister Yiannis Vroutsis when he announced that talks over public sector reform would have to be postponed until later in the day so he could brief the IMF chief on the progress made so far via telephone.

His departure was followed by that of European Commission envoy Matthias Mors and the ECB's representative Klaus Mazuch.

Sources suggested that the meeting was interrupted after the troika failed to reach an agreement with the minister over changes to the public sector pay structure, pensions and severance pay.