WASHINGTON (REUTERS) - Wall Street opened higher on Friday as robust labour market data boosted optimism about the strength of the US economy.

The report by the US Labor Department showed that nonfarm payrolls rose by 255,000 in July. Economists had expected a rise of 180,000.

The report also showed that the unemployment rate was flat at 4.9 per cent, staying below the 5 per cent mark associated with full employment. Average hourly wages rose by 8 cents. "(The data) cements the view that the economy is improving despite the recent negative news from GDP," said Aaron Kohli, interest rate strategist at BMO Capital Markets in New York.

The data suggests that the April and May jobs data was an aberration and that June was more consistent with what is going on in the economy, he said. The June employment number was revised up to 292,000 from 287,000.

However, inflation running below the Fed's 2 per cent target and weaker-than-expected GDP growth amid global uncertainty could deter the central bank from pulling the trigger in the near term.

The chances of a rate hike doubled to 18 per cent in September after the jobs report, and rose to 36.8 per cent from 29.4 per cent in December. Those numbers do not rise significantly even until July next year, according to CME Group's FedWatch tool.

"I'm not sure this is enough to move the needle in either direction for the Fed," said Curt Long, chief economist at National Association Of Federal Credit Unions in Washington.

At 9:42 a.m. ET (9.42 p.m Singapore time), the Dow Jones Industrial Average was up 135.31 points, or 0.74 percent, at 18,487.36. The S&P 500 was up 11.67 points, or 0.54 percent, at 2,175.92. The Nasdaq Composite was up 34.94 points, or 0.68 percent, at 5,201.18.

Seven of the 10 major S&P 500 sectors were higher, led by a 0.89 percent rise in financials.