Onyx Investments, a subsidiary of Oman's sovereign wealth fund, is seeking a judgement from an Omani court that would allow it to claim collateral on notes issued to fund a $20bn real-estate project that ran into trouble as a result of the regional property crisis.

Onyx, in an emailed statement, said it had instructed the note trustees, Bank of New York Mellon and Bank Muscat, to ask the Primary Commercial Court of Oman for a "debt recovery judgement" in relation to a special-purpose vehicle known as Blue City Investments 1 Ltd, which issued $925m of notes in 2006 to fund the real-estate project. The judgement "is required in order to subsequently commence enforcement of the project security in Oman," Onyx said.