Investors remained cautious about Greece's debt, however, and pushed risk premiums on the nation's bonds higher despite a European Union rescue plan hammered out last weekend.
Intel's reported forecast-beating results late on Tuesday that reinforced hopes for an acceleration in the tech sector's recovery. Its shares rose 3.1 percent.
J.P. Morgan stock jumped 3.3 percent after it reported earnings that topped estimates.
Indexes of financial shares and technology shares led gains on the broad S&P 500, which broke above the 1,200 mark for the first time since September 2008.
In the US, the Dow Jones Industrial Average rose 62.88 points, or 0.57 percent, to 11,082.30, also the highest since September 2008. The Standard & Poor's 500 Index increased 8.77 points, or 0.73 percent, to 1,206.07 and the Nasdaq Composite Index climbed 28.19 points, or 1.14 percent, to 2,494.18.
White House spokesman Robert Gibbs on Wednesday cited a rise in US stocks as a sign that President Barack Obama's measures to boost the economy were working.
"We've seen three consecutive quarters of economic growth. The measure that some use is that of the stock market, which, prior to me making this comment, appeared to be above 11,000," Gibbs told reporters.
"There are those that seem to continue to deny that we're making progress on the economy despite all available information to the contrary," Gibbs said.
The White House is usually cautious about commenting on the
stock market.
In Europe, the pan-European FTSEurofirst 300 gained 0.6 percent to reach an 18-month closing high at 1,105.32 points.
European banking and tech stocks led the rally, rising on the strength of the US results.
Dutch chip equipment maker ASML also reported that its first-quarter orders beat even the most optimistic expectations.
"It looks like nothing is going to stop this market from going higher at the moment, anyway, even any possible Greek debt default," said David Morrison, market strategist at GTF Global in London.
World stocks as measured by MSCI gained 1 percent to its highest level since the financial crisis was coming to a head in September 2008. Its emerging market counterpart rose more than 1.2 percent.
Japan's Nikkei gained 0.39 percent.
The euro pared gains against the dollar after rating agency Moody's told Reuters there was still a greater than 50 percent chance of a rating cut for debt-stricken Greece in the next 12 to 18 months.
The dollar surrendered gains against the yen and fell against the dollar over disappointment that Federal Reserve Chairman Ben Bernanke in Congressional testimony gave no new guidance on US interest rates.
At midday in New York, the dollar edged lower against a basket of major trading-partner currencies, with the US Dollar Index off 0.48 percent. The euro rose 0.43 percent to $1.3664, and the dollar declined 0.15 percent to 93.07 yen.
Spot gold prices rose $8.95, or 0.78 percent, to $1,159.10.
