Nomura International has won £1.1m (€1.7m) in damages and costs from Credit Suisse First Boston (CSFB) in a UK commercial court after suing the Swiss-American investment bank over unpaid credit derivative contracts linked to convertible bonds.

The derivatives were referenced to Railtrack, the UK infrastructure operator that was put into administration by the UK government in 2001. Nomura and CSFB entered into a credit default swap contract in which the Japanese bank, which owned the convertible bonds, bought protection on Railtrack defaulting on its debt.