WASHINGTON (MarketWatch) -The index for U.S. consumer prices fell 0.1% in June, reflecting the third straight monthly decline, the Labor Department reported Friday. Lower gasoline costs mostly accounted for the decline. The closely followed core rate, seen as a better gauge of inflationary trends, rose 0.2% but still remains very low. The core rate excludes volatile food and energy prices. Economists surveyed by MarketWatch had predicted a flat reading in overall consumer prices and a 0.1% increase in the core rate. Over the past 12 months, CPI has climbed 1.1% and the core has risen a scant 0.9%, according to government data.