The number of Americans filing new claims for unemployment benefits fell more than expected last week, in the latest sign of tightening labor market conditions. Initial claims for state unemployment benefits dropped 10,000 to a seasonally adjusted 278,000 for the week ended Nov. 1, the Labor Department said on Thursday. The four-week moving average of claims, considered a better measure of labor market trends as it irons out week-to-week volatility, fell 2,250 to 279,000, the lowest reading since April 2000.