By Deborah Levine
NEW YORK (MarketWatch) -- Treasury prices added to gains and the dollar inched up after an index on U.S. consumer sentiment fell to 66.6 in September, while analysts had expected a slight improvement. Yields on 10-year notes, (UST10Y 2.73, -0.03, -1.19%) , which move inversely to prices, fell 6 basis points to 2.71%. The dollar index (DXY 81.31, +0.07, +0.08%) , which tracks the performance of the greenback against a basket of six major currencies, rose to 81.332, from 81.239 late Thursday. Versus the yen, the dollar (USDYEN 85.7000, -0.0900, -0.1049%) bought 85.69 yen compared with ¥85.78 in late North American trading Thursday. The euro (EURUSD 1.3066, -0.0010, -0.0765%) changed hands at $1.3062, from $1.3080 in late Thursday action.