An oil tanker is seen off the port of Bandar Abbas, southern Iran.

Oil prices fell 1 percent on Tuesday, with U.S. crude breaking below $50 per barrel for a second straight day ahead of weekly data that could show a build in domestic inventories.

Analysts said verbal jockeying among the Organization of the Petroleum Exporting Countries (OPEC) created uncertainty about potential output cuts at its meeting next month, noting that a particular worry was Iraq's exclusion from the plan.