Roller coaster oil prices' latest rebound moved up a gear on Oct. 12 as buyers gradually purged memories of the spectacular sell-off a week before. Benchmark North Sea Brent crude for November delivery was trading 49 cents higher at $21.72 a barrel, building on the day before's gains of more than 50 cents. The renewed upswing has repaired damage sustained last week when heavy selling from speculative funds took Brent four dollars down from recent 33-month peaks at $24.30 a barrel. "There has been good buying all round. Trade, locals and speculators are buying into this bounce," a dealer said. Renewed gains have breathed fresh life into an eight-month-old rally from sub-$10 lows powered by OPEC output curbs and recovering global demand.