Wall Street closed lower Friday as crude oil prices continued to decline.
The Dow fell 30 points to end the day at 20,547 and the S&P 500 lost seven points to 2,348.
The Nasdaq decreased six points to finish trading at 5,910.
A six-month production cut agreement between OPEC and Russia that was implemented at the beginning of the year may not be extended because of worries participants of the deal have so far failed to agree on an extension, according to experts.
That helped to push crude prices down 7 percent this week.
At the final bell Friday, American benchmark West Texas Intermediate was trading at $49.56 -- a 2.2 percent decline.
International benchmark Brent crude was at $51.90 -- a 2.1 percent loss.
By Ovunc Kutlu in New York