Treasurys extended a rally, pulling yields down further, while major U.S. stock indexes held on to small gains after the Institute for Supply Management's closely watched service index

edged into contraction territory in May. The ISM Services PMI fell to 49.9% from a reading of 51.6% in April. A reading of less than 50% indicates a contraction in activity. The services

gauge last signaled a contraction in June of last year. The yield on the 10-year Treasury note was down 7.5 basis points near 4.384% after the data. Yields and debt prices move in opposite

directions. The Dow Jones Industrial Average was holding on to a gain of 51 points, or 0.1%, while the S&P 500 was up 0.2% and the Nasdaq Composite rose 0.2%.