The International Monetary Fund is estimating it needs to raise up to $600 billion (389 billion pounds) in new resources to lend to countries struggling with the fallout from the growing euro zone debt crisis, IMF sources said on Wednesday.

While the IMF estimates it will need $500 billion of the money to lend to member countries, the remaining $100 billion will be used as a protection buffer, the sources, who were present at an IMF board discussion on the issue on Tuesday, told Reuters.

The IMF also estimated that there would be a $1 trillion global financing gap over the next two years if global economic conditions worsened considerably, the sources added.

The IMF currently has a lending capacity of about $380 billion. IMF sources said a European commitment to inject 150 billion euros ($200 billion) into the IMF is included in the $600 billion estimate.

The new figures comes as G20 deputies from developed and developing nations gather in Mexico on Wednesday for preliminary talks on boosting the IMF's war chest, with concerns growing that the euro zone debt crisis has worsened.

IMF Managing Director Christine Lagarde said on Tuesday she met with the IMF board to assess whether the- global lender needs additional funds to respond effectively to the euro zone crisis and said IMF management would explore options for increasing the Fund's firepower.

The IMF has warned it will cut global growth projections for 2012 when it updates its forecast on January 24. Weakening global prospects raises fears that more countries will need rescuing by the IMF, especially if capital markets freeze up completely.

(Reporting By Lesley Wroughton; Editing by Theodore d'Afflisio)