The talks, which began at breakfast Wednesday, finally ended in the wee hours of Thursday with a compromise after discussions that saw Britain's George Osborne warn he would not sign anything that would make him "look like an idiot."
The special meeting was called to find a common EU position on the Basel III regulation, which will require banks to increase their capital buffers to avoid a repeat of the massive bailouts they received in the 2008 financial crisis.
"We have an agreement, it needs technical work before it is technically done," Danish Economy Minister Margrethe Vestager, whose country holds the rotating EU presidency, said after almost 16 hours of highly technical talks.
She said the ministers resolved 20 issues during the day and that a final agreement would come at their next meeting on May 15 after "technical verifications on the last outstanding issues."
The ministers were sharply divided, with Britain and Sweden seeking freedom to impose tougher capital requirements than under Basel while the Franco-German bloc wants all 27 EU nations to follow the same standards for more than 8,000 banks.
Osborne, whose country is home to Europe's biggest financial centre, told his colleagues during the televised debate that he was "not prepared to say something that is going to make me look like an idiot five minutes later."
German Finance Minister Wolfgang Schaeuble had voiced concern that the EU may never reach an agreement if a deal was not found on Wednesday, warning that such an outcome would be "disastrous."
Paris and Berlin want a "maximum harmonisation" of the rules, fearing that allowing nations to set higher thresholds would spark a race for the biggest reserves that would divert funds away from investments and lending.
The fraught discussion came in the midst of concerns about the health of the Spanish banking sector, still reeling from a real estate bubble that burst in 2008.
The Basel III rules, which governments must start to implement in 2013, require all banks to raise total core reserves to 7.0 per cent from 2.0 per cent at the moment.
Denmark proposed a compromise that would allow governments to impose an extra 3.0 per cent buffer. It later raised it to 5.0 per cent with certain conditions attached to it.
EU governments must agree on a position before taking the deal to the European Parliament.
France and Italy backed the compromise but Britain and Sweden stuck to their guns. London and Stockholm say governments have the right to set the standards they want and refuse to let the European Commission have a say in such decisions.
"Either we have strong banks or the taxpayers take the risk, and I prefer to have strong capital in the banks than to take risks with the taxpayers," Swedish Finance Minister Anders Borg said before the talks started.
Polish Finance Minister Jacek Rostowski pointed to the "sad example" of Ireland, which was bailed out after its public deficit blew up following a banking crisis.
"A group of countries including Poland, the Czech republic, Sweden and the UK are very determined to see that banking systems in the future should be kept as healthy as we expect the fiscal side, budgetary side, to be kept," he said.
"This crisis is a crisis in which fiscal and banking system crisis feed on each other. It's not enough to deal with one, you need to deal with both at the same time."