HONG KONG/SINGAPORE (REUTERS) - Noble Group will have to fork out more than double in interest margin on a US$1 billion (S$1.35 billion) unsecured loan it is raising with banks, as a fall out of the credit rating downgrade the commodity trader has faced, sources familiar with the matter said on Tuesday.

The company has launched a 364-day revolving credit facility, which will pay an interest margin of 225 basis points over LIBOR compared with 85 basis points interest margin for last year's one-year US$1.1 billion loan, said the sources, who declined to be identified as the information is not public.

The loan comes on top of a US$2.5 billion secured financing that Noble is seeking in the United States from its lenders and will help it to partially repay its debt maturing in May.

Loss-making Noble has mandated eight banks including Societe Generale, MUFG, HSBC and DBS as lead arangers, the sources said.

Noble, HSBC and Societe General declined comment. Bank of Tokyo-Mitsubishi UFJ (MUFG) and DBS had no immediate response.