Greece has formally asked the eurozone for a six-month extension of a loan agreement as it seeks to revise the terms of an international bailout. Talks between Greece and its European creditors collapsed this week amid disagreement over the future of German-backed austerity. Greece had been given a Friday deadline to request a new extension of its bailout and loans. Germany has rejected Greece’s demands, saying its extension request “is not a substantial proposal for a solution.” On Wednesday, the European Central Bank reportedly agreed to free up billions of dollars in emergency credit to Greek banks.