NEW YORK, March 9 : Wall Street investment banking giant Goldman Sachs is pitching hedge funds a financial product that allows them to take a short or long position on corporate loans, a source familiar with the matter said. The product, known as a total return swap, is a derivative contract that allows investors to profit from changes in market value of the loans, the source said. No trades have been executed using this strategy so far, the source said. The Financial Times earlier reported the