Oil prices fell on Tuesday after Saudi Arabia said it would play a “responsible role” in energy markets, although sentiment remained nervous ahead of new U.S. sanctions on Iran’s crude exports that start next month.  Benchmark Brent crude oil LCOc1 was down 55 cents a barrel at $79.28 by 0735 GMT. U.S. light crude CLc1 was 35 cents lower at $69.01. The U.S. sanctions on Iranian oil begin on Nov. 4, and Washington has said it wants to stop all of Tehran’s fuel exports. Saudi Arabia says it will keep markets supplied despite its increasing isolation over the killing of Saudi journalist Jamal Khashoggi, and there are signs that crude exports from the Middle East are rising. There has been some concern that Saudi Arabia might cut […]