The Supreme Court on Thursday declared Air Marshal Arshad Mehmood Malik's appointment as head of the Pakistan International Airlines (PIA) "illegal", saying he could not hold two posts at the same time.

A three-member bench headed by Chief Justice Gulzar Ahmed asked Malik to choose between serving in the Pakistan Air Force or as Chief Executive Officer (CEO) of PIA.

Earlier, on January 21, the SC had rejected Malik’s appeal against the Sindh High Court’s decision to stop him from performing any functions as CEO of the national airline until a final decision in the present case is made.

"Arshad Mehmood Malik should resign from the air force and permanently join PIA. Only one thing can be done, either work in PAF or PIA," remarked the chief justice.

The court noted that the national airline required a "permanent chairman" who can run it along professional lines and make it profitable.

The court asked Malik to submit a definite answer by the next hearing which will be in the first week of March.

When Salman Akram Raja, representing the PIA's board of governors told the court that former Air Marshal Nur Khan had also worked for the national carrier, the chief justice remarked that "they were big people and should not be compared to anyone".

Justice Sajjad Ali Shah said that if the court accepted the advocate's argument, stating that if "the union employees would not let PIA function unless there was the stick of the army", then the government "should close all its offices".

The SC also rejected PIA's report about the mysterious sale of an Airbus plane owned by the national flag carrier in 2017, observing that it had only conducted a "paper investigation" into the matter.

The court directed the National Accountability Bureau to continue its investigation into how the plane was sold.

The mysterious sale of the PIA plane had caught the attention of the SC on Feb 13 when it questioned whether the sale of the aircraft — a public property — amounted to a national offence or not.