The number of Americans filing new claims for unemployment benefits rose less than expected last week, suggesting an acceleration in job growth in September. Initial claims for state unemployment benefits increased 12,000 to a seasonally adjusted 293,000 for the week ended Sept.20, the Labor Department said on Thursday. A Labor Department analyst said there were no special factors influencing the state level data. The jobless claims report showed the number of people still receiving benefits after an initial week of aid edged up 7,000 to 2.44 million in the week ended Sept. 13.