Fears of a collapse in earnings have not been borne out thus far. Though the earnings season has been under way a short time, some 72 percent of companies have beaten estimates, albeit from a significantly lowered bar.

Goldman Sachs (GS.N) shares ended up 0.3 percent at $97.98 even as its quarterly profit fell 12 percent. Coca-Cola Co (KO.N), which also topped consensus forecasts, rose 1.6 percent to $77.69.

Frustration over Bernanke's lack of specifics about stimulative quantitative easing measures, or QE3, in testimony before a Senate committee drove equities lower early in the trading session.

But the Fed chief said policymakers would consider a range of tools to further stimulate growth if it became clear unemployment was not falling or if deflation risks mounted.

"We do expect the Fed to launch QE3, possibly by as early as August," said Oliver Pursche, president of Gary Goldberg Financial Services in Suffern, New York. "The only game in town to revive or raise GDP growth is the Fed."

Pursche cautioned about reading too much into earnings that beat lowered forecasts. Analysts sharply cut their estimates over the last year. Second-quarter S&P 500 earnings are expected to rise 6 percent from a year ago, down from an estimated of 9.2 percent on April 1, according to Thomson Reuters data.

"When you look at Coke, when you look at Goldman, when you look at some of the reports last week the beats were there, but they're based on pretty low expectations," he said.

In the last month, most gains on the S&P have come from the telecommunications services, consumer staples and healthcare sectors, which are considered defensive, safer plays. Industrials, technology and materials have posted losses in that period.

Healthcare products maker Johnson & Johnson (JNJ.N) cut its full-year profit forecast on Tuesday. But the shares, which have risen 12 percent since the start of June, climbed 0.8 percent to $69, hitting their highest level in more than 3 years.

The basic materials sector was among gainers on the S&P 500, with a 5.1 percent jump in shares of fertilizer company Mosaic (MOS.N) after it reported better-than-expected quarterly results.

The Dow Jones industrial average .DJI rose 78.33 points, or 0.62 percent, at 12,805.54. The Standard & Poor's 500 Index .SPX added 10.03 points, or 0.74 percent, at 1,363.67. The Nasdaq Composite Index .IXIC gained 13.10 points, or 0.45 percent, at 2,910.04.

"If the economy is weakening, it means (Bernanke) will probably come back to the table. He hasn't spent that bullet yet and until he does, the markets are probably going to hold up," said Bruce Bittles, chief investment strategist at Robert W. Baird & Co in Nashville.

"From a technical side we see improvement in the trend in the market, but the leadership remains with defensive sectors, which tells us there's not a lot of appetite for risk."

The S&P has posted losses in seven of the last nine sessions, falling about 1 percent.

The relatively slight losses amid a worsening economic picture has been credited in part to historic low bond yields and to a vigilant Fed.

Shares of financial company State Street Corp (STT.N) fell 6.4 percent to $41.31 after it said second-quarter net income fell.

Excitement around Yahoo Inc's (YHOO.O) new chief executive, Marissa Mayer, formerly a top executive at Google (GOOG.O), faded and Yahoo shares slipped 0.3 percent at $15.60 after a 2 percent rise. Yahoo has cycled through three CEOs in a year.

About 6.31 billion shares changed hands on the New York Stock Exchange, the Nasdaq and Amex, compared with the year-to-date daily average of 6.22 billion shares.

Advancers beat decliners by a ratio of about 2 to 1 on the NYSE and on the Nasdaq by about 5 to 4.

(Additional reporting by Rodrigo Campos, editing by Kenneth Barry)

• A Permanent Economic Emergency