Moody's credit rating agency has placed the ratings on commercial paper and medium-term notes issued by Dublin investment vehicle Rhinebridge on review for a possible downgrade.

The development came less than a fortnight after the agency placed the conduit's subordinated debt on review for a possible downgrade.

It puts yet more pressure on the fund set up by the troubled German business bank, IKB Deutsche Industriebank, whose exposure to the US subprime mortgage crisis led to a government-backed bailout last month.

Launched just last June, Rhinebridge is an off balance-sheet conduit which specialises in buying structured credit instruments, such as collateralised debt obligations, backed by such assets as credit card receivables and mortgages.

After encountering serious trouble with Rhineland, another conduit, IKB had to bring Rhinebridge on to its own balance sheet last month to facilitate an €80 million injection of fresh capital.

With Moody's making clear yesterday that Rhinebridge's problems persist, some reports in Germany have already speculated it will have to be wound up.

"Moody's rating action reflects the further deterioration of the market value of Rhinebridge's portfolio since placing the subordinated debt on review, its continuous inability to fund, as well as a breach of its net cumulative outflow [ liquidity] test.

"Moody's notes, however, that the quality of the asset portfolio remains high, with a weighted average rating of Aa1," the agency said.