Berlin  - Level One, a British-run property investor, has declared insolvency in one of Germany's biggest real-estate collapses, an administrator disclosed Wednesday in Berlin.

Level One invested mainly in substandard communist-era public housing in eastern Germany and Berlin.

It ran out of credit to renovate the apartments as bank lending tightened up. While German has experienced neither a real-estate bubble nor a price slump, Level One was caught out by the British slump. Its German properties are hard to let without upgrading.

It owns 20,000 apartments and 500 commercial properties. Many were prefabricated concrete buildings cheaply built in communist times.

Insolvency administrator Rolf Rattunde said the Level One group owed 1.5 billion euros (2 billion dollars). Last week 38 companies in the group applied for protection from creditors and more applications were due next week.

"It's one of Germany's biggest real-estate failures," he said.

The consortium owning Level One includes a real-estate investor, Cevdet Caner, who is based in London and Monaco, he said.

The German units are directly owned by companies registered in the British Channel Island territory of Jersey.

The owner of the Jersey companies had filed for protection in London in September, he said. Its creditors included Credit Suisse International, JP Morgan and Royal Bank of Scotland. dpa