NEW YORK — Concerns about the world economy helped tug U.S. stocks lower on Monday as worries mount over Greece’s standoff with its creditors.

Major indexes headed lower at the opening of trading, following European markets down. A rebound in crude oil drove energy stocks higher.

With no major reports on the U.S. economy to hold their attention, investors looked abroad.

“There’s still a lot of uncertainty around Greece,” said Jack Ablin, chief investment officer at BMO Private Bank. “It’s one of these tectonic plates shifting around the financial system.”

Greece’s new prime minister, Alexis Tsipras, set his government on a collision course with the country’s creditors. In a speech on Sunday, Tsipras declared an end to a regimen of budget cuts and tax increases and said he would push for a short-term loan to give the country and its creditors time to negotiate a new arrangement to replace its bailout program. Greece and its international creditors were expected to take up the issue later this week.

For investors, the worry is that if Greece drops the European currency, it could have unpredictable consequences for the wider financial system. One fear is that other countries with much larger economies might follow Greece out the door.

The Standard & Poor’s 500 slipped 8.73 points, or 0.4 percent, to close at 2,046.74. Of the 10 sectors in the index, only energy companies finished higher.

The Dow Jones industrial average fell 95.08 points, or 0.5 percent, to 17,729.21, while the Nasdaq composite fell 18.39 points, or 0.4 percent, to 4,726.01.

This week marks the halfway point for the fourth-quarter earnings season, and the results are shaping up better than Wall Street had expected. Seven out of 10 big companies have turned in higher profits than analysts had forecast, putting overall earnings on track to rise 7 percent for the full quarter, according to S&P Capital IQ.

In other trading Monday, U.S. crude oil rose $1.17, or 2.3 percent, to close at $52.86 a barrel in New York, while brent crude, the international benchmark, rose 54 cents to $58.34 in London. The gains came as OPEC said that it expects demand for crude to rise this year and U.S. output to fall.

Higher prices for crude oil helped lift stocks in companies tied to the oil industry. Nabors Industries, a driller, and National Oilwell Varco each gained 3 percent.

Major markets in Europe closed lower. France’s CAC-40 lost 0.9 percent, and Germany’s DAX fell 1.7 percent. Greece’s main Athens Exchange lost 4.7 percent.

Interest rates on government bonds in Italy and Spain jumped, though they still remain near historic lows.

In Asia, most major stock markets closed lower following news that China’s imports fell nearly 20 percent over a year earlier. Exports were also weak, heightening concerns about the world’s second-largest economy.

Hong Kong’s Hang Seng fell 0.6 percent while South Korea’s Kospi slipped 0.4 percent. Japan’s Nikkei 225 added 0.4 percent.

Back in the U.S., prices for government bonds edged up, pushing long-term interest rates down. The yield on the 10-year Treasury note slipped to 1.95 percent.

In the commodity markets, gold gained $6.90 to settle at $1,241.50 an ounce, while silver rose 38 cents to $17.07 an ounce. Copper lost half a penny to $2.85 a pound.