Stocks edged lower Thursday as talks over keeping Greece solvent stalled and got extended into the weekend.
Health care stocks rose sharply after the Supreme Court upheld the Affordable Care Act's insurance subsidies.
The Dow Jones industrial average lost 75.71 points, or 0.4 percent, to 17,890.36. The Standard & Poor's 500 index fell 6.27 points, or 0.3 percent, to 2,102.31 and the Nasdaq composite fell 10.22 points, or 0.2 percent, to 5,112.19.
Stocks had been flat to slightly higher the first half of the day. But that momentum was soon lost and Greece worries turned the market lower in the early afternoon.
The bitter standoff between Greece and its international creditors was extended into the weekend, days before Athens has to meet a crucial debt deadline which could decide whether it defaults on its debt and has to drop out of the euro.
A key meeting of eurozone finance ministers broke up Thursday without agreement on Greece's rescue package, intensifying doubts about whether Athens can make a 1.6 billion euro ($1.8 billion) debt payment to the International Monetary Fund that is due Tuesday.
An agreement on a drastic Greek tax and austerity reform package is necessary for creditors to unfreeze 7.2 billion euros (8.1 billion dollars) in bailout money.
Greece has a small economy and its debt problems have been long known by investors. However, the possibilities of destabilizing the euro and the implications of a country defaulting on its debt have weighed on investors for months now.
“It's fair to say markets have been somewhat complacent about the risk related to Greece, and it's all coming to a head now,” said Ben Mandel, a global strategist at JPMorgan Multi-Asset Solutions. “It could cause some volatility next week.”
Health care stocks, especially hospital operators, rose sharply after the Supreme Court upheld the nationwide tax subsidies under President Barack Obama's health care overhaul. The ruling will preserve health insurance for millions of Americans who are not covered under state-owned exchanges. Humana rose 7 percent, HCA Holdings rose 9 percent, Tenet Healthcare rose 12 percent and Cigna rose 2 percent.
U.S. government bond prices fell. The yield on the 10-year Treasury note rose to 2.40 percent from 2.37 percent the day before.
In the energy markets, the price of oil fell on continuing concerns that high supplies of gasoline and diesel will keep a lid on crude demand. Benchmark U.S. crude fell 57 cents to close at $59.70 a barrel in New York. Brent crude, a benchmark for international oils used by many U.S. refineries, fell 29 cents to close at $63.20 in London.
In other futures trading on the NYMEX, wholesale gasoline fell 1.9 cents to close at $2.037 a gallon. Heating oil fell 1.4 cents to close at $1.862 a gallon. Natural gas rose 9.1 cents to close at $2.850 per 1,000 cubic feet.
Gold fell $1.10 to $1,171.80 an ounce, silver fell four cents to $15.81 an ounce and copper was flat at $2.62 a pound.