US stocks traded higher on Thursday, sending the Dow Jones Industrial Average to refresh all- time intraday high for three days in a line which was on track of setting new closing high, boosted by an improving US jobs market.

The main stock indices opened higher following a modestly rising equity market in Europe after Standard & Poor's Ratings Services Thursday revised the outlook on Portugal's long-term rating to stable from negative and strong demand for Spanish bond pushed the yield lower.

Both the European Central Bank and Bank of England expectedly kept their interest rates unchanged Thursday.

The number of Americans applying for initial jobless claims last week decreased to a seasonally adjusted 340,000 from the previous week's revised figure of 347,000, according to the US Labor Department. The four-week moving average, a smoother indicator, was 348,750, a decrease of 7,000 from the previous week 's revised average of 355,750.

Meanwhile, labor productivity of nonfarm business sector decreased at a 1.9 percent annual rate during the fourth quarter of 2012, the US Labor Department also reported on Thursday.

Among other data, the trade deficit in January increased to 44. 4 US billion dollars from 38.1 billion dollars in December, higher than market expectation, the US Commerce Department announced Thursday.

A rally in financial sector pushed the Standard & Poor's 500- stock Index higher. The Federal Reserve will release a first round of stress-test results for banks after the closing bell.

In corporate news, shares of Boeing surged after the National Transportation Safety Board said Thursday it still had not found root cause of January battery fire on Boeing 787.

Gap shares also rose after the clothing retail reported Thursday that its same store sales in February increased 3 percent, beating analysts' estimates.

In midday trading, the blue-chip Dow was up 48.91 points, or 0. 34 percent, to 14,345.15. The broader S&P 500 rose 3.42 points, or 0.22 percent, to 1,544.88. The tech-rich Nasdaq Composite Index gained 7.99 points, or 0.25 percent, to 3,230.36.

Thursday's rally followed a gain in the previous session, boosted by positive private sector hiring.