ATHENS — Only a day after grim predictions of financial and social collapse in Greece, a scramble appeared underway to work out the details of a new bailout package to bring the country back from the brink of falling out of the euro.

As details of the new offer emerged, it appeared that Prime Minister Alexis Tsipras was capitulating to demands on harsh austerity terms that he urged his countrymen to reject in the referendum last Sunday, like tax increases and various measures to cut the costs of pensions.

But Mr. Tsipras sought a three-year bailout loan totaling 53.5 billion euros (about $59 billion) and asked creditors to commit to discussing restructuring the nation’s massive debt. The amount was more than it would have been without a nationwide banking shutdown that has pummeled the economy. If granted, it would come on top of 240 billion euros in bailout loans Greece has received since 2010. Mr. Tsipras seemed to have gained ground on debt relief, his one bedrock demand. Germany’s finance minister, Wolfgang Schäuble, finally gave a little on that Thursday, admitting that “debt sustainability is not feasible without a haircut,” or write-down of debt, even if he then appeared to backtrack.

Donald Tusk, a former prime minister of Poland and the president of the European Council, said on Twitter that any “realistic proposal from Athens needs to be matched by realistic proposal from creditors on debt sustainability to create win-win situation.”