WASHINGTON – The number of Americans filing new claims for unemployment benefits rose marginally last week, the latest suggestion that the economy was regaining some momentum as the year winds down. The smaller-than-expected increase in weekly jobless claims reported by the Labor Department on Thursday followed recent data showing retail sales unexpectedly rising in November, while single-family housing starts and building permits scaled 1-1/2-year highs. Those reports prompted economists to boost their growth estimates for the fourth quarter. The economy had appeared in danger of stalling at the start of the quarter. There was even more good news on inflation, with other data on Thursday showing significantly more progress made toward returning it to the Federal Reserve’s 2% target in the third quarter than previously reported.