Hypo Real Estate, the German bank caught up in the past two weeks' wave of collapses, said Saturday the government-backed bail-out it was hoping for had collapsed.
The mortgage lender said assurances of loans from several other financial institutions had expired.
Munich-based Hypo Real Estate, which mainly lends to commercial projects and to build public facilities, said it was assessing the impact on its various divisions and was seeking alternatives.
The German government and the banking industry had announced on Monday a 35-billion-euro (50-billion-dollar) set of guarantees to enable Hypo Real Estate to resume short-term lending.
But negotiations on the details dragged during the week, with several banks reluctant to contribute.

German exports plunged in November to record the biggest fall in nearly two decades, data released Thursday showed, as the deepening world economic downturn hits Europe's biggest economy.
When the Spirit rover landed on Mars five years ago, no one expected it or its sister rover Opportunity to make it to their first birthdays, let alone their fifth.
The San Antonio Spurs turned up their trademark defense down the stretch to turn back another opponent.
US singer and Academy Award winner Jennifer Hudson, 27, dominated the nominations for the 40th NAACP Image Awards.
After the Taipei Zoo received two giant pandas from China, another Taiwan zoo said Friday it is seeking to receive a pair of pandas from China.