New York - Another sharp fall in oil prices pulled down energy stocks on Wall Street on Monday, pushing the main US indices to a loss after last week's record highs.
Meanwhile, Yahoo shares tumbled after Verizon announced it would buy the company's web properties for $4.8 billion.
The Dow Jones Industrial Average finished down 0.4% from Friday's close at 18 493.06.
The broader S&P 500 fell 0.3% at 2 168.48 and the tech-heavy Nasdaq dropped 0.1% at 5 097.63.
US benchmark WTI crude hit a three-month low of $43.13 a barrel after losing 2.4% in New York trade, hitting the shares of oil majors and service companies.
ExxonMobil lost 1.9% and Chevron dropped 2.5%. Schlumberger, the largest services firm, fell 1.1% and Halliburton 2.9%.
Bill Lynch of Hinsdale Associates said buyers were taking a breather after a heady climb.
"We've been up four consecutive weeks, it would be an opportune moment to take some profits," he said.
Yahoo shares fell 2.7% after the long-expected Verizon deal was announced. Verizon lost 0.4%.
The deal will see the Yahoo News, email and other assets integrated into Verizon's recently acquired AOL unit, while Yahoo will be left as a separate investment company holding Yahoo Japan and the company's most valuable asset, a huge stake in China's Alibaba Group.
"Yahoo is a company that has changed the world, and will continue to do so through this combination with Verizon and AOL," chief executive Marissa Mayer said.
Markets were turning their focus to the Federal Reserve meeting on Tuesday and on Wednesday and what the Fed, which is not expected to make any immediate policy shifts, says about the rest of the year.
"Suspicions are building that the Fed may go back to laying the groundwork for another rate hike in the near future," said Patrick O'Hare of Briefing.com