By Lucia Mutikani WASHINGTON (Reuters) – 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 appear…