London — Belgian bank KBC seized assets from one of the diamond industry’s most storied names as it seeks to recover unpaid loans, according to court documents. KBC is seeking to recover €26m from Exelco, and had bailiffs search the firm’s Antwerp offices as well as offices belonging to De Beers and ABN AMRO, where Exelco might also hold assets, court documents seen by Bloomberg News show. Exelco also has credit lines with Standard Chartered, said people familiar with the matter, who asked not to be identified because it is private. Exelco’s financial troubles are another blow to an industry struggling with thin manufacturing margins and the withdrawal of trade finance. Standard Chartered, one of the two leading lenders, said last year that it was exiting the diamond financing business, while KBC’s Antwerp Diamond Bank, which accounted for about 10% of the financing market at its peak, is being wound down.