First Interstate Bancorp said it has sold a portfolio of risky commercial loans to a Philadelphia company for about $55 million as part the Los Angeles-based bank holding company's restructuring. Congress Financial bought substantially all of the asset-based loan portfolio of First Interstate Commercial Corp. The loans carry a high interest rate for commercial customers who are unable to obtain traditional financing. They are secured by assets, such as inventory or accounts receivable. First Interstate said most of the accounts are in Portland, Ore., and Denver. Congress Financial said it will retain key personnel from First Interstate's Portland and Denver offices.