(Close): Opec's decision to maintain production levels and the subsequent fall in oil prices dominated share movements on Wall Street on a curtailed trading day following Thanksgiving.
The slump in oil prices hit shares in energy firms, with Chevron down 5.4% and Exxon Mobil 4.1% lower.
The Dow Jones closed flat at 17,828.24 while the S&P 500 index dropped 0.25% at 2067.56.
The tech-heavy Nasdaq index rose 0.09% at 4791.63.
While energy firms suffered, shares in airlines rose on hopes that the fall in oil prices will lead to cheaper fuel.
Southwest Airlines rose 6.4%, Delta Airlines was up 5.4% and Jetblue Airways jumped 7.5%.
Oil prices continued to slide later on Friday with Brent crude at under $72 a barrel and US crude below $68.
