Timeline: Euro zone meetings and gatherings in 2011

(Reuters) - Europe overcame its latest obstacle on Thursday with Germany approving a stronger euro zone bailout fund, but a series of challenges remains as Greece tries to secure more aid to avoid imminent default.

Some national parliaments have yet to approve an agreement to increase the size and powers of the European Financial Stability Facility (EFSF). Even if passed, many say the $440 billion fund does not have enough finances to carry out its increased mandate.

An intractable debt crisis has forced euro zone finance ministers to meet regularly over this year. Here is a timeline of those meetings and gatherings in 2011.

January 17, 2011 - Eurogroup meeting of euro zone finance ministers in Brussels to discuss the euro zone rescue fund.

-- Euro zone finance ministers rejected the idea of enlarging the EFSF during discussions, the Dutch finance minister said the next day.

January 18 - Ecofin meeting of European Union finance ministers in Brussels.

-- European finance ministers only inched forward toward beefing up the EFSF and preparing new stress tests for the region's shaky banks, dashing market hopes of quicker action.

February 4 - Summit of European Union heads of state and government.

-- Germany and France tried to win backing for a pact to strengthen the euro zone economy, but many other EU states were angered by what they saw as a 'fait accompli' and the measures contained in it.

February 14 - Eurogroup meeting of euro zone finance ministers in Brussels.

-- Draft conclusions the next day, obtained by Reuters, show EU ministers will support competitiveness plans that the European Commission laid out in January.

March 4 - Fourteen EU leaders, hosted by Finland, meet to prepare a comprehensive response to the euro zone debt crisis.

-- Finland said the common will was there for European leaders to agree a pact, that would call on member states to enact national legislation on debt. Ireland wanted easier terms on Dublin's financial bailout loans, but was told there would be "no free lunches."

March 15 - Ecofin meeting of EU finance ministers in Brussels.

-- Euro zone officials said that they are likely to agree on the details of bolstering the region's bailout fund soon, and the reformed EFSF should be operational by the summer.

-- On March 12 euro zone leaders agreed that the capacity of the EFSF should be raised to its full 440 billion euros from the current 250 billion, but left it up to finance ministers to work out how.

March 21 - Eurogroup meeting of euro zone finance ministers in Brussels.

-- European finance ministers met to hammer out details of the safety net mechanism for euro zone economies that get into financial difficulty.

March 24/25 - Full summit of EU heads of state and government in Brussels.

-- EU leaders confirmed that the EFSF, would have a higher effective lending capacity by June.

April 8/9 - Informal meeting of European finance ministers in Hungary.

-- EU finance ministers urged Portugal to commit to reforms and defended the region's austerity steps. Portugal on April 6 became the third euro zone country after Greece and Ireland to ask for EU and IMF financial aid.

May 16 - Eurogroup meeting of euro zone finance ministers in Brussels.

-- Euro zone finance ministers approved a 78 billion euro bailout for Portugal but insisted that Lisbon ask private bondholders to maintain their exposure to its debt.

May 17 - Ecofin meeting of European Union finance ministers in Brussels.

-- Europe's top financial officials broke a taboo and acknowledged for the first time that Greece may have to restructure its debts.

June 14/15 - Eurogroup meeting of euro zone finance ministers in Luxembourg

-- Euro zone finance ministers met to discuss a second financing package for debt-laden Greece. Euro zone officials said there was no progress on how to involve the private sector.

June 20 - Eurogroup meeting of euro zone finance ministers and Ecofin meeting of EU finance ministers in Luxembourg.

-- A visit to Athens by Greece's international lenders was announced after euro zone finance ministers delayed approving the next 12 billion euro ($17.1 billion) tranche of aid for Greece.

June 23/24 - Summit of EU heads of state and government in Brussels.

-- Euro zone leaders endorsed the treaty setting up the European Stability Mechanism (ESM) -- a permanent mechanism for resolving sovereign debt crises -- from mid-2013.

July 3 - Extraordinary Eurogroup meeting of euro zone finance ministers in Brussels:

-- Euro zone finance ministers have approved a 12 billion euro installment of Greece's bailout, but signaled that the nation must expect significant losses of sovereignty and jobs.

July 11/12 - Eurogroup meeting of euro zone finance ministers in Brussels.

-- Euro zone finance ministers promised longer debt maturities and a more flexible rescue fund to help Greece and other EU debtors, but they set no deadline to act

July 21 - Meeting of euro zone heads of state and government in Brussels.

-- Euro zone leaders agreed on giving the rescue fund broader powers to prevent contagion spreading from the euro zone debt crisis.

September 6 - Finance ministers of the Netherlands, Finland and Germany meet in Berlin.

-- The Dutch finance minister said talks with Finland and Germany had not resolved a row over a bilateral deal between Finland and Greece granting the Nordic country collateral for contributing to a new Greek bailout package.

September 16/17 - Informal meeting of ministers and central bank governors in Wroclaw, Poland.

-- EU finance ministers broke no new ground in dealing with the euro zone debt crisis. However, U.S. Treasury Secretary Timothy Geithner made an appearance to urge Germany to provide more fiscal stimulus to the slackening euro zone.