Energy stocks weigh on US markets

(Close): After a strong performance on Monday, US stocks fell on Tuesday with energy companies hit by falls in oil prices.

The Dow Jones closed 198 points down to 17,976.31, while the broader S&P 500 index dropped 18 points to 2,067.89. The technology-focused Nasdaq index was 46 points lower at 4,900.89.

Oil prices fell more than a dollar a barrel, pushing energy firms lower.

Shares in Chevron fell by 1.8% while Exxon Mobil dropped 0.7%.

Oil prices fell with talks between Iran and six world powers over Tehran's nuclear programme approaching a close.

A deal could allow Iran to increase its oil exports.

Brent crude futures fell $1.15 to $55.14 a barrel, while US crude dropped $1.02 to $47.47.

Charter Communications rose 5% after it announced it was buying rival cable operator Bright House Networks in a $10.4bn deal.