PIA is facing its worst crisis in history as Pakistan State Oil (PSO) has cut its fuel supply over unpaid dues. The move forced the airline to cancel 537 flights since October 13. On Thursday, as many as 49 domestic and international flights were cancelled from Karachi, Lahore, Islamabad, Quetta, Multan, Peshawar and other cities after the PSO slashed its fuel supply to the PIA, sources said. Meanwhile, PIA CEO Amir Hayat asked all employees to maintain a concerted focus on ensuring organisational compliance through closely-knit teamwork ahead of the airline's privatisation.