Hiring in the United States slowed in May to weakest in nearly two years, the Labor Department reported Friday. Nonfarm payrolls increased by 78,000, the lowest since August 2003, according to a survey of business establishments. Meanwhile, the unemployment rate slipped to 5.1% from 5.2%, based on a separate household survey. It's the lowest unemployment rate since September 2001. Economists were expecting much stronger job growth in May, forecasting an average gain of 186,000, according to the survey conducted by MarketWatch. The weak hiring will likely encourage bond bulls, who have pushed the yield on the benchmark 10-year note to 3.90% this week. However, the Federal Reserve is likely to remain on its steady path of "measured" interest rate hikes at its meeting at the end of June, economists say. Payroll growth in March was revised down by 24,000 to 122,000, while April payroll gains were unrevised at 274,000. Average hourly wages increased 3 cents, or 0.2%, to $16.03 in May. Wages are up 2.6% in the past year.