0817 GMT - A preliminary deal between the U.S. and Iran is unlikely to materialize before the first quarter of next year, according to BMI analysts. "Extended disruptions to regional oil flows will see price pressures extend and build across the coming three to six months, compounded by ongoing supply-side constraints stemming from the Russia-Ukraine war," they say. "Prices will zigzag higher, as repeated cycles of escalation and deescalation between Washington and Tehran meet with progressively lower inventory levels and fewer fundamental brakes on future rallies." BMI raised its oil price forecast, saying it now sees Brent crude at an average of $93 a barrel this year, from $83 a barrel previously.