Stock index futures pointed to a strong open on Wall Street Tuesday, with futures for the S&P 500 up 1.97 percent, Dow Jones futures up 1.62 percent and Nasdaq 100 futures up 1.61 percent at 3:54 a.m. EDT.

Many eyes will be on banks after Swiss lender UBS AG (UBSN.VX) (UBS.N) said it plans to slash around 3,500 jobs, almost half of them from its investment bank, as it seeks to shave some 2 billion francs from annual costs by the end of 2013.

European stocks were up 1.6 percent in early trading, led by a rebound in cyclical shares such as industrials and miners, but volumes were thin as investors remained wary of another false start after last week's rebound from a 20-percent nosedive quickly fizzled out.

Market players were also cautious ahead of U.S. Federal Reserve Chairman Ben Bernanke's key speech at an annual central bank conference in Jackson Hole, Wyo., Friday, during which he could unveil fresh measures to revive the struggling economy.

The Fed chairman looks set to discuss ways the central bank could tweak its balance sheet as a means to put further pressure on medium- and long-term interest rates and anchor them at low levels. These could be implemented in September and October at coming Fed meetings.

After the closing bell Monday, shares of Goldman Sachs (GS.N) fell 2.4 percent to $104. Goldman CEO Lloyd Blankfein has hired Reid Weingarten, a high-profile Washington defense attorney, according to a government source familiar with the matter.

Investigations continue of Goldman and its role in the 2007-2009 financial crisis.

Shares in Goldman Sachs traded in Frankfurt (GS.F) were down 5.8 percent.

On the macro side, investors awaited data on new home sales for July and the Federal Reserve Bank of Richmond's August indexes on area manufacturing and service sectors.

Brent crude rose toward $109 on Tuesday, while U.S. crude was up more than $1 as fighting in Libya continued and in anticipation of a fall in U.S. crude stockpiles.

Asian markets took heart Tuesday from HSBC's China flash purchasing managers' index (PMI), which, although showing the factory sector was likely to slow slightly for a second consecutive month in August, indicated the motor of the global economy in recent years was still growing robustly.

It suggests there's still plenty going on and it's business as usual, Martin Angel, a dealer at Patersons Securities in Australia, told Reuters.

European stock index futures pointed to gains, with futures for the Euro STOXX 50 up 0.8 percent, Germany's DAX up 1 percent and France's CAC up 0.8 percent, while financial bookmakers called London's FTSE 100 up around 0.5 percent.

World stocks remain deep in negative territory for the month, with MSCI's all-country world index about 19 percent below its May high.

The euro firmed a touch but remained vulnerable as traders awaited flash PMI data for Germany, France and the euro zone, with a weak number likely to exacerbate fears about the region.

Japan's Nikkei share average rose 1.2 percent on Tuesday, while MSCI's broadest index of Asia Pacific shares outside Japan gained 2 percent.

The MSCI index is down nearly 14 percent for the month, and about 18 percent below its April high. A decline of 20 percent or more is the rule-of-thumb definition of a bear market.

World stocks have been tumbling since the beginning of August -- and perceived safe havens such as gold, U.S. Treasuries and Japanese government bonds have rallied -- on fears of a slide back into recession for the United States and growing concerns that Europe's politicians are failing to contain its sovereign debt crisis.

Today's gain is likely a technical rebound, with the lack of political momentum from the United States and Europe on resolutions to their economic issues leaving investors with little conviction, said Han Chi-hwan, a market analyst at Daewoo Securities in Seoul.

Most markets extended gains after the Chinese flash PMI from HSBC, designed to preview China's factory output before official data, which showed the index edging up to 49.8 in August from July's final reading of 49.3.

That left the index just below the 50-point mark that separates expansion from contraction, but HSBC itself believes a reading as low as 48.0 in China would still point to annual growth of 12-13 in industrial output and 9 percent in GDP.

Risks of a hard landing are still remote, said Qu Hongbin, an economist at HSBC.

There had earlier been vague market rumors that the number would be much weaker.

The Australian dollar, which is sensitive to expectations of Chinese demand for Australia's commodities such as iron ore and coal, rose to stand up 0.6 percent on the day around $1.0465.

London metal exchange copper rose 1 percent , although Shanghai futures were weaker.

Resource stocks were prominent amongst the gainers and S&P 500 futures rose 0.9 percent, pointing to Monday's tentative rally on Wall Street continuing.

But many investors remained pessimistic about the outlook for rich world economies, particularly the euro zone, where the big fear is that the debt crisis that has swamped Greece, Portugal and Ireland will spread to bigger, harder to save economies such as Spain or Italy.

Spot gold soared to the latest in a succession of all-time highs above $1,910 an ounce and was on course for its biggest monthly rise in 29 years.

We are not hearing much good news out of Europe or the United States, said Darren Heathcote, head of trading at Investec Australia.

For the time being investors are happy looking at gold as safe haven in these troubled times, and will continue to do so until we see something positive and sustainable.

U.S. crude oil gained 0.8 percent to around $85.10 a barrel , after falling on Monday on hopes that Libyan exports would restart soon as the country's six-month-old civil war neared an end with rebel troops entering Tripoli.

It could take months before oil can start to flow again from Libya, said John Vautrain, a director at energy consulting firm Purvin & Gurtz.

I think there was a lot of euphoria on Monday. But the whole country is not completely pacified yet and we don't have an organized government. A lot is lacking.

The euro traded around $1.4380, up a little on the day but below Monday's high around $1.4434, as markets awaited flash PMI surveys from the euro zone's big economies.

The current stabilization in risk is conditional on European PMIs not disappointing sharply, warned Sebastien Galy, analyst at Societe Generale.

Weaker growth in Germany would lead the market to think that help for peripheral Europe will be harder to come back.

The dollar index, which tracks the U.S. currency's performance against a basket of major currencies, was a touch weaker at 74.031, but off Monday's low of 73.814 .

Worries about more action from Swiss and Japanese authorities to weaken their currencies helped support the dollar index.

Against the yen, the dollar was at 76.75 yen, off a record low around 75.94 set last Friday. The Swiss franc traded at 0.7880 francs, having carved out a slim trading band between 0.7800 and 0.8000.

Japanese government bonds eased after their rally of recent months, with September 10-year futures falling 0.22 point to 142.55, while the benchmark 10-year yield rose 2.5 basis points to 1.010 percent.

(Reporting by Koh Gui Qing in Beijing, Ian Chua in Sydney, Alex Richardson and Rujun Shen in Singapore and Ju-min Park nd Claire Jim in Seoul; Editing by Ramya Venugopal)