European stocks .FTEU3 were up around 0.7 percent, while Japan's Nikkei average .N225 jumped 2.4 percent to hit its highest closing level since a massive earthquake and tsunami triggered a radiation crisis a year ago, buoyed by indications the U.S. Federal Reserve may keep its supportive monetary policy.

Brent crude held steady above $125 while the dollar stayed near a one-month low against a currency basket on Tuesday after Bernanke kept the door open for more monetary easing, though debt worries left the euro struggling to extend gains versus the U.S. currency.

The European Commission has opened an in-depth investigation into the proposed acquisition of Goodrich Corp (GR.N) by United Technologies Corp (UTX.N), both U.S. aviation equipment makers, the European Union's executive said on Tuesday.

Apple Inc (AAPL.O) Chief Executive Tim Cook has jetted into China for talks with government officials as he seeks to clear up a pile of problems in the firm's biggest growth market, from its contested iPad trademark to treatment of local labor.

Orders flowed normally through BATS Global Markets on Monday, bringing a sigh of relief that the core trading business of the nation's third-largest stock exchange remains on track despite a high-profile trading snarl on Friday.

Discount retailer Dollar General Corp (DG.N) said it will buy back about $300 million in shares from Buck Holdings L.P., the company's controlling shareholder.

Bausch & Lomb said it agreed to buy Ista Pharmaceuticals Inc (ISTA.O) for about $500 million in cash to broaden its portfolio of eye health products.

On the macro front, investors awaited the S&P/Case-Shiller Home Price Index for January, due at 1300 GMT, while the Conference Board releases March consumer confidence at 1400 GMT.

The S&P 500 rebounded from its worst week so far this year to retake a four-year high on Monday after Federal Reserve Chairman Ben Bernanke signaled supportive monetary policy will remain even though the job picture has begun to improve.

The Dow Jones industrial average .DJI shot up 160.90 points, or 1.23 percent, to 13,241.63 at the close. The Standard & Poor's 500 Index .SPX gained 19.40 points, or 1.39 percent, to 1,416.51. The Nasdaq Composite Index .IXIC climbed 54.65 points, or 1.78 percent, to 3,122.57.

(Reporting by Blaise Robinson; Editing by Hans-Juergen Peters)

• A Permanent Economic Emergency