Oil deepens loss on Iran talks
Oil fell for a third straight session on Tuesday, with Brent crude tumbling 12 percent for the month, as world powers entered into intense negotiations with Iran for a nuclear deal that could bring more of its oil to an oversupplied market.
The tumble was proof of the hurdles oil faced in establishing a bottom for prices since the selloff that began in June on worries of a supply glut. US crude fell 11 percent for the quarter.
