U.S. stock investors could scramble to pick up some of the market's recent best performers this week as the quarter comes to an end, putting the spotlight on energy and industrial companies.

But worries about Japan, the Middle East and oil prices will persist and keep uncertainty high, analysts said, even as the VIX, the CBOE Volatility Index <.VIX>, slid 27 percent over the past week.

Another driver could come from economic data, with the U.S. government's March payrolls report -- the most widely watched economic indicator of the month -- due on Friday.

Economic data lately has taken a backseat to geopolitical events, with Japan's massive earthquake and tsunami sparking fears of a nuclear disaster in the country and driving the most recent pullback in stocks.

But many expect window dressing, where fund managers sell stocks with big losses and buy ones with big gains to spruce up their portfolio's quarterly performance, to dominate trading.

I think a number of people viewed the harshness of the sell-off as an opportunity to pick up some inappropriately punished stocks, said Michael Strauss, chief economist of Wilton, Connecticut-based Commonfund.

The strategy contributed to a bounceback late last week, with the Dow Jones industrial average <.DJI> and Nasdaq <.IXIC> posting their best weeks since July. The benchmark Standard & Poor's 500 <.SPX> had its best week since early February.

Analysts say the stock market's recent performance has been strongly influenced by expectations for the upcoming earnings reporting period, which kicks off the second week of April.

Oracle's upbeat outlook late Thursday and its stock's 1.6 percent rise on Friday is one example of that, while the energy sector has benefited from the view that the run-up in oil prices will mean stronger-than-anticipated results for producers and refiners.

KING OIL

Energy, up about 14 percent since the start of the quarter as measured by the S&P energy index <.GSPE>, is by far the sector with the biggest gains for the quarter to date.

Brent crude oil prices are trading at $115 a barrel, just off recent 2 1/2-year highs, as Western powers last weekend launched a military campaign in oil producer Libya and unrest escalated in other countries, including Yemen and Bahrain.

While higher oil prices are seen as an overall drag on the global economy, they boost the earnings and shares of energy companies.

If they're able to sell oil at anywhere near the spot prices, they should post a really good quarter, and we're already seeing that in the stock prices, said Fred Dickson, chief market strategist of D.A. Davidson & Co. in Lake Oswego, Oregon.

Marathon Oil , up about 40 percent for the quarter to date, has the fourth-best gain in the S&P 500 for the last three months, and energy companies dominate the quarter's top performers. El Paso Corp is up 31 percent and Valero Energy is up 30 percent.

Among the stocks in the Dow Jones industrial average, Chevron Corp , up 17 percent for the quarter, is the Dow's top gainer so far for the quarter.

Gary Bradshaw, portfolio manager at Dallas-based Hodges Capital Management, which he described as heavy in energy, said the firm likes Exxon Mobil Corp , Chevron and ConocoPhillips . But he said Hodges also likes small-capitalization energy companies, including Brigham Exploration , up 30 percent so far for the quarter.

INDUSTRIAL STRENGTH

Among top sectors, energy is followed by industrials <.GSPI>, up about 6 percent so far for the quarter; consumer discretionaries <.GSPD>, up 4 percent, and technology <.GSPT>, up 3 percent.

Caterpillar , up 16.5 percent for the quarter, has the second-best gain among the Dow's 30 stocks.

Strauss predicts investors will turn even more to industrial and agricultural companies, seen likely to benefit from the economic recovery in the United States and growth elsewhere.

The manufacturing component of the industrial sector has had a very nice economic cycle upturn, and it's happened at a time when we haven't been able to rebuild depleted inventory positions, Strauss said.

That should help U.S. companies overcome the shock of what's happening overseas, including debt problems in Portugal, he said. According to a Reuters poll released last week, the S&P 500 should end the year with a gain of 11 percent.

Friday's payrolls report for March should show improvement in the slow-to-recover labor market. Last month, the government's monthly jobs report showed the jobless rate slipped to almost a two-year low in February.

Investors are going to become more stock-specific going forward, even within better-performing areas like the cyclical sectors, said Scott Billeaudeau, portfolio manager of Fifth Third Asset Management in Minneapolis.

There are certain areas that still have significant leverage and they haven't overspent, he said, noting he owns Cummins Inc , down about 5 percent for the quarter. I think there are lots of legs in a company like that.

Earnings for the S&P 500 as a group are expected to rise 14 percent for the quarter from the year before, according to Thomson Reuters data.

(Reporting by Caroline Valetkevitch; Editing by Jan Paschal)

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