The army chief is arguably the most powerful person in Pakistan, with the military having ruled the country for more than half its 69-year history since independence from Britain. General Bajwa will likely take charge of the world's sixth-largest army by troop numbers in a formal handover on Tuesday, when General Sharif, who is no relation to prime minister Nawaz Sharif, formally retires. The appointment of Bajwa is expected to help reset fraught relations between the military and the civilian government in a nuclear-armed nation of 190 million people. Lieutenant General Zubair Hayat has been appointed chairman of the joint chiefs of staff committee. 'On the advice of Pakistani Prime Minister Muhammad Nawaz Sharif, President Mamnoon Hussain has approved the promotion of Lieutenant General Zubair Mehmood Hayat and Lieutenant General Qamar Javed Bajwa,' the prime minister's office said. As well as controlling security, the army operates a vast business empire in the country and often dictates key areas of Pakistan's foreign policy, including relations with historic foe India and its western neighbour Afghanistan. General Sharif, 60, becomes the first army chief in more than 20 years to step down on time. Several previous military leaders had obtained extensions to their three-year terms.