NEW YORK (AFP) - Wall Street continued to move higher on Tuesday (Feb 11) with two key US stock indices edging to record closes as fears ebbed that the viral outbreak in China would cause global economic disruption.

The broad-based S&P 500 increased 0.2 per cent to finish the session at 3,357.75, while the tech-rich Nasdaq Composite Index rose 0.1 per cent to close at 9,638.94.

Meanwhile, the benchmark Dow Jones Industrial Average finished flat at 29,276.34.

Testifying before Congress, Federal Reserve chairman Jerome Powell warned that the new coronavirus outbreak in China "could lead to disruptions... that spill over to the rest of the global economy."

But that appeared to have little impact on investors who had steeled themselves for worse.

"I don't think it was a newsmaking commentary and that's why the market is relatively mixed today," Alan Skrainka of Cornerstone Wealth Management said of Powell's testimony.

Other news buoying investor sentiment was a federal judge's ruling giving the go-ahead to a proposed merger between T-Mobile and Sprint that would create the third-largest telecom company in the United States.

Sprint closed up 77.5 per cent, while T-Mobile's shares rose by 11.8 per cent.