Quietly, the American Bankers Association, that stalwart of conservative American banking, has blessed a new “subprime” commercial loan product.

The ABA has formally endorsed the Proceed Business Loan program created by Promontory Interfinancial Corp., which was rolled out earlier this month. “ABA members can use the product to establish relationships with customers, gain deposits and accounts without adding balance sheet risk,” says Lisa Gold Schier, senior vice president of the ABA’s Corporation for American Banking unit.

Call it what you will, but the Proceed Business Loan is essentially a “subprime” commercial loan product. The product gives credit against the business borrowers’ credit card receivables. The annualized percentage rate conforms to the FDIC’s guidance for small dollar loans, so it will not exceed 36%. It’ll probably get close to that, however.

Brian Christie, vice president of business alliances, Promontory Interfinancial, says 50 banks are signed up for the program. Enrollment spiked within the last week and a half because of the ABA endorsement.

Of course, the ABA won’t call it subprime commercial lending (Schier referred all my questions to Promontory), but any company borrowing against its card receivables at rates of 30% or 35% is doing so because it has to.

You know the expression, “You do what you have to do”? Even conservative banking has succumbed to that dictum during these tough times.