Noble Group Ltd., the commodity trader fighting for survival, lost support from one of its key banks as Singapore’s DBS Group Holdings Ltd. cut lending, according to a person with knowledge of the matter. Shares sank. DBS sold its $60 million stake in Noble’s $1.1 billion revolving credit facility due in May next year, and also closed some other financing to the company, the person said, asking not to be named because the matter is private. It’s unclear whether the bank still has any remaining credit exposure to the trader.