Strong demand for quality cotton pushed prices higher on Saturday where most of the buying originated from Punjab spinners. The undertone remained firm and outlook optimistic.Floor brokers said that currently around 70 per cent demand for cotton was originating from Punjab-based spinners and only 30pc by the Sindh industry, reports the Dawn.However, world cotton markets once again gave mixed trend with New York and India coming under renewed selling pressure. The Chinese market, on the other hand, remained firm, brokers said.