Job opportunities in the United States unexpectedly increased in August, which may prompt the Federal Reserve to raise interest rates next month. The Labor Department's monthly survey on job openings and labor turnover released on Tuesday indicated that job openings, a measure of labor demand, surged by 690,000 to 9.610 million at the end of August. July's data was revised upward to show 8.920 million job openings instead of 8.827 million in the previous reading. Economists surveyed by Reuters had anticipated 8.800 million job openings in August.