If the decision is taken to intervene, the ECB and national central banks would start buying the bonds when markets open on Monday, the source said.

It was not clear whether the ECB would issue any statement after the meeting, expected to take place on Sunday evening, the source added.

The ECB reactivated its controversial sovereign bond-buying programme last Thursday but has so far only bought small quantities of Irish and Portuguese bonds, seeking tougher austerity measures from Italy.

Italian Prime Minister Silvio Berlusconi announced late on Friday plans to bring forward balancing the budget by one year to 2013, enshrine a balanced budget rule in the constitution and push through welfare and labour market reforms after talks with trade unions and employers.

Copyright Reuters, 2011