US STOCKS-Wall St flat on earnings, IBM pressures Dow

* IBM (NYSE: IBM - news) shares fall on weak revenue, pressuring Dow

* Transport index hit new high, Norfolk rallies

* BlackBerry (Berlin: RI1.BE - news) rallies for third straight day

* Indexes: Dow off 0.2, S&P flat, Nasdaq up 0.4 pct

By Ryan Vlastelica

NEW YORK (Frankfurt: HX6.F - news) , Jan 22 (Reuters) - U.S. stocks were little changed on Wednesday, as a mixed bag of recent corporate earnings failed to give investors confidence to push equities higher, with the S&P 500 near record levels.

While the Nasdaq advanced, the Dow fell for a second straight day, again pressured by weak results from one of its components.

International Business Machines Corp lost 3.5 percent to $181.88, the biggest drag on both the Dow and S&P 500, after the tech giant missed revenue expectations for a fourth straight quarter amid weakening demand, particularly in growth markets like China.

The results followed similar disappointments from Verizon , Travelers and Johnson & Johnson (NYSE: JNJ - news) , which weighed on the Dow on Tuesday.

IBM's decline offset modest gains from fellow component United Technologies Corp (NYSE: UTX - news) , which rose 0.6 percent to $115.68 after it reported fourth-quarter earnings that topped Wall Street estimates, although revenue fell shy of expectations.

"We've seen significant decreases in a company's ability to deliver on earnings this quarter... however, we've also seen signs that the top-line growth we've been looking for is starting to emerge," said Kristina Hooper, head of portfolio strategies at Allianz Global Investors in New York.

"Seeing a broad-based top-line growth trend would really speak to the health of the economy... that's allowed for the market to hang in there despite some disappointments."

With 16 percent of the S&P 500 having reported, about 61 percent have topped profit expectations, according to Thomson Reuters data, compared with the long-term average of 63 percent. More than 66 percent have topped revenue expectations, over the 55 percent average over the past four quarters.

About eight companies have issued negative outlooks for every positive one, which would mark the lowest ratio on record should it continue.

The Dow Jones industrial average was down 40.04 points, or 0.24 percent, at 16,374.40. The Standard & Poor's 500 Index was up 0.47 points, or 0.03 percent, at 1,844.27. The Nasdaq Composite Index was up 15.31 points, or 0.36 percent, at 4,241.07.

After a 29.6 percent jump in the S&P 500 in 2013, buoyed by the Federal Reserve's massive stimulus, the S&P has shaved off a mere 0.2 percent so far in 2014 as investors look to corporate profits for evidence of growth as the Federal Reserve winds down its market-friendly bond purchases.

"In general valuations are stretched, though there are still areas of opportunity for investors who are able to be more selective," aid Hooper, who helps oversee $436 billion in assets under management. "Focusing on areas with more growth may be worth paying up for."

Also in earnings, Advanced Micro Devices Inc (NYSE: AMD - news) slumped 10.8 percent to $3.72 after forecasting a steeper-than-expected fall in current quarter revenue, while Coach Inc (NYSE: COH - news) tumbled 6 percent to $49.38 as the S&P's worst performer after it said sales in North America fell further in the final quarter of 2013.

On the upside, Norfolk Southern Corp jumped 4.7 percent to $94.39 after its earnings beat expectations, helping lift the Dow Jones Transportation average to a record high.

Nuance Communications (NasdaqGS: NUAN - news) rose 8.4 percent to $16.15 after giving a first-quarter outlook, helping to boost the Nasdaq. U.S.-listed shares of BlackBerry also buoyed the tech-heavy index, jumping 5.5 percent to $10.47. Shares of the smartphone maker are up more than 22 percent over the past three sessions.

Cloud software maker VMWare Inc (NYSE: VMW - news) said it would buy privately-held mobile security company AirWatch, in a deal valued at about $1.54 billion, to tap into rising demand for software security, sending its shares up 2.1 percent to $99.37.