By Victor Reklaitis and Barbara Kollmeyer, MarketWatch

NEW YORK (MarketWatch) -- U.S. stocks closed slightly lower Tuesday, as an effort to build on Monday's strong gains ran out of steam.

No top-tier economic reports came out, but mergers-and-acquisitions news helped to limit losses, with FedEx Corp. (FDX) among the S&P 500's biggest advancers after the shipping giant said it would buy Dutch logistics company TNT Express.

The S&P 500 (SPX) dipped by 4.29 points, or 0.2%, to close at 2,076.33. Only health care (XLV) and energy (XLE) avoided losses among the index's 10 sectors. Energy-related stocks rose along with the U.S. oil benchmark, (CLK5) which jumped 3.5% and settled at its best level so far this year.

Meanwhile, the Dow Jones Industrial Average (DJI) inched lower by 5.43 points, or less than 0.1%, to end at 17,875.42, after the blue-chip gauge briefly showed a gain of more than 100 points. The Nasdaq Composite (RIXF) fell by 7.08 points, or 0.1%, to finish 4,910.23.

Tuesday's slip came amid slow trading, as composite volume was at its second-lowest level so far this year, according to a Dow Jones markets data group. But the reversal to the downside still indicates some wariness among investors ahead of first-quarter earnings season, which unofficially kicks off Wednesday with Alcoa Inc.'s (AA) report after the close.

The three main indexes all remain up between 0.5% and 0.6% for the week after Monday's rally, which was attributed to bets that last Friday's weak jobs report could delay interest-rate hikes.

This week's gains by equities should be accompanied by a dose of caution, according to some market experts. The monthly average for job creation in 2015 is still above 200,000 so far, and the dismal March report could see a revision when next month's data are published, Stan Shamu, market strategist with IG, said in a note.

"As far as the Fed is concerned, it is unlikely that one month's data will make all the difference, and we know the central bank only has to be reasonably confident that inflation and jobs will trend toward target over the next couple of years for it to act," Shamu said.

Among chart watchers, BTIG's Katie Stockton said her team is "not convinced that the pullback has fully matured yet." A breakout above "intraday resistance" near 2,089 by the S&P 500 "would be an 'all-clear' signal," said Stockton, BTIG's chief technical strategist, in a note Tuesday. The S&P scored a record close on March 2, but has since held below that record level for five weeks.

Tuesday's economic news:Job openings rose to a 14-year high (http://www.marketwatch.com/story/job-openings-rise-to-14-year-high-in-february-2015-04-07) of 5.13 million in February, the Labor Department said.

Before the market's open, Minnesota Fed President Narayana Kocherlakota, a leading dove and nonvoting member, said in a speech that no rate hikes are needed until 2016's second half (http://www.marketwatch.com/story/no-fed-rate-hike-needed-until-second-half-of-2016-kocherlakota-2015-04-07).

Individual movers: Shares of FedEx Corp (http://www.marketwatch.com/story/fedex-to-buy-tnt-express-for-48-billion-in-cash-2015-04-07).(FDX) closed 2.7% higher after the company announced a $4.8 billion deal to buy TNT Express NV (TNTEY).

In what could be the biggest U.S. leveraged buyout of the year so far, Informatica Corp.(INFA) agreed to be taken private by Permira Advisors LLC and the Canada Pension Plan Investment Board in a $5.3 billion deal (http://www.marketwatch.com/story/informaticas-stock-rallies-after-53-billion-buyout-deal-2015-04-07). Informatica's stock finished up 4.3%.

Read more about Tuesday's jumpiest stocks in the Movers & Shakers column (http://www.marketwatch.com/story/dave-busters-international-speedway-earnings-in-focus-2015-04-07)

Other markets:Oil rose, erasing early losses (http://www.marketwatch.com/story/oil-eases-with-us-stockpiles-production-back-in-focus-2015-04-07) and adding to Monday's big advance. Gold prices ()(GCK5) fell after a gain on Monday, while the dollar (DXY)pushed higher against major rivals (http://www.marketwatch.com/story/us-dollar-bides-time-while-aussie-jumps-after-rba-holds-steady-2015-04-07).

In a catch-up move as investors returned from a long holiday weekend, European stocks (http://www.wsj.com/articles/permira-cppib-poised-to-take-informatica-private-in-5-billion-deal-1428398039) finished with gains. Asian stock markets closed mostly higher (http://www.marketwatch.com/story/asian-shares-mostly-higher-following-wall-street-gain-2015-04-06).

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