* China April exports tumble from year ago, investment jumps
* Bernanke says U.S. economy, dollar strong
* Asia stocks fall for second day, follow Wall Street
* India's March industrial output falls more than expected
* Nissan loses $2.4 bln in Q4, sees more losses ahead
By Zhou Xin and Alan Wheatley
BEIJING, May 13 (Reuters) - China disappointed markets on Tuesday with a sharp drop in exports in April that overshadowed strength in capital spending and dampened optimism that a global economic recovery might be around the corner.
Stock markets have rallied in the past two months on bets that the worst of the deepest global downturn in six decades might be over, and recent policymakers' comments also reflected cautious optimism about the prospects for a gradual recovery.
Federal Reserve Chairman Ben Bernanke was the latest to strike a positive note, voicing confidence in the inherent strength of the U.S. economy and its banks' ability to raise cash.
The sense of returning confidence was also apparent in Bank of Korea's decision on Tuesday to hold interest rates steady for a third straight month and its forecast that Asia's fourth-largest economy would probably experience "mild growth" in the months ahead.
But China's economic data underscored that the world economy was not out of the woods yet.
While fixed-asset investment in urban areas soared more than 30 percent in the first four months in response to Beijing's $585 billion stimulus, a bigger than expected 22.6 percent annual slump in exports showed global demand remained subdued.
Analysts took heart from signs that Beijing's efforts to prop up domestic demand seemed to be bearing fruit, but said global conditions remained difficult, even as both China's imports and exports rose compared with March levels.
"The future of the world economy remains uncertain, and it's really hard to be optimistic about China's trade prospects," said Qi Jingmei, an economist with the State Information Centre, a government think-tank in Beijing.
(For a related Graphic, click: http://graphics.thomsonreuters.com/059/CN_TRD0509.jpg)
Asia's other emerging giant, India, also disappointed, reporting March industrial output fell 2.3 percent from a year earlier, more than a 0.5 percent drop forecast in a Reuters poll.
With Japan and much of Europe seen mired in recession until some time next year, markets are pinning their hopes on China's ability to rev up growth with the help of massive government spending and a U.S. recovery in the second half of this year.
STRONG DOLLAR
Bernanke said the dollar would retain its status as the world's top reserve currency and the strength of the U.S. economy would underpin its value.
"I think the dollar will be strong. I think it will be strong because the U.S. economy is strong," he said in response to a question after delivering a speech at a conference hosted by the Atlanta Fed.
The dollar edged down against a basket of currencies near a four-month low, but held firm against the euro.
Bernanke also said he was encouraged by the ability of U.S. banks to boost capital following the results of government "stress tests" on how they would endure a sharp downturn.
"Many of the banks are well ahead in finding private-sector options for increasing their common equity, and several have announced plans for new equity issues," he said.
On Monday, central bankers meeting at the Bank for International Settlements in Basel summed up their qualified hopes for the future.
"We are, as far as growth is concerned, around the inflection point in the cycle," said European Central Bank President Jean-Claude Trichet.
STOCKS RETREAT
But while recovery hopes have fuelled a nearly two-month rally in global stock markets, job cuts, corporate losses, rising bad debts and mixed economic data all served to keep investors' enthusiasm in check.
Stocks in Asia retreated for a second day on Tuesday, following Wall Street losses overnight, with Tokyo shares down 1.6 percent and markets elsewhere in Asia-Pacific down 1.7 percent.
The auto industry, one of the hardest hit by the collapse in global consumer spending, has been a consistent source of sobering reminders as to how long and painful a recovery may be.
The struggling U.S. giant General Motors said on Monday a bankruptcy filing had become more probable and Japan's No.3 carmaker Nissan said it lost $2.4 billion in January-March and predicted more losses in the current year.
And while policymakers are already charting their post-crisis strategies, investors fret over the ballooning cost of stimulus packages and company bailouts.
On Monday, the White House raised its budget deficit forecast for the fiscal year to end-September to $1.84 trillion, a whopping 12.9 percent of gross domestic product, from an earlier prediction of a 12.3 percent gap.
And in Australia, which for years had boasted fiscal surpluses, markets expect the government to propose a record deficit in its budget later on Tuesday. [ID:ID:nSYD8710] (Reporting by Reuters correspondents worldwide; Writing by Tomasz Janowski; Editing by Ian Geoghegan)