Brent crude was still heading for a weekly gain, having rallied on Thursday in response to strong German economic data that lifted the oil demand outlook and easing concern about a rapid rise in Iranian oil supplies. Brent crude (LCOc1) slipped 5 cents to $56.52 a barrel by 0856 GMT (4.56 a.m. EDT), on track for its third weekly gain in four. Top exporter Saudi Arabia was the driving force behind the policy shift. While some OPEC members are urging output cuts to boost prices, Saudi Arabia has shown no sign of a rethink.