Factors — companies that purchase invoices from retail suppliers at a discount, promoting cash flow — are tightening their requirements, and scrutinizing the creditworthiness of retailer debtors (the invoice payors) more closely.  Factors are approving lesser amounts, or withholding them altogether for suppliers whose retail customers appear at risk of defaulting because of consistently weak earnings or losses.  The pullback by factors comes on the heels of the tightening of credit by banks, and may make it difficult for some weak retailers to stock needed inventory.  “According to a new study by BDO Seidman LLP, an accounting and consulting organization, nearly half of the chief financial officers at U.S. retailers have experienced a tightening of credit by their lenders.  In addition, more than a third of the CFOs reported a reduction of planned inventory purchases for 2008.”  The Wall Sreet Journal Sept. 30, 2008  Paid subscription may be required.