FRANKFURT (Reuters) -- Troubled German bank IKB faces the threat of further write-downs on its own loan portfolio in addition to the impact of the U.S. sub-prime crisis, Germany's Focus magazine reported.

The size of the financial holes was not known, the magazine reported, quoting sources close to the company.
The risk provisions of over 1 billion euros ($1.47 billion) were not sufficient to cover its loan portfolio of some 30 billion euros, the magazine said.
IKB, which lends to roughly one in 10 of Germany's biggest companies, nearly collapsed under the strain of losses on its investments in risky U.S. home loans but was saved by a bailout spearheaded by state lender KfW in August.
IKB was not immediately available for comment on Saturday. KfW declined to comment.