The Saudi Arabia-led Islamic Military Alliance to Fight Terrorism (IMAFT) was announced in December 2015.
On Dec 15 the same year, Bangladesh Foreign Minister AH Mahmood Ali said that Dhaka has accepted Riyadh's invitation to join the military coalition.
The government, however, is yet to commit Bangladeshi troops in IMAFT-led military campaigns.
Saudi Arabia said in a statement in late 2015 that the alliance was an effort to combat the Islamic State and terrorism. But since then, Riyadh has not spelled out details on how it would operate.
The IMATF, whose headquarters will be in the Saudi capital of Riyadh, has not been supported by Iran.
On Friday, Pakistan's Defence Minister Khawaja Asif broke the news of General Sharif's appointment as the commander-in-chief during a talk-show on a Pakistani TV channel.
Khawaja told the TV channel that an agreement was finalised a few days back, but said he did not have details of it at that moment.
The announcement led to a flood of criticism of Sharif, who until recently had been lauded for his three-year term as the head of Pakistan’s half a million-strong army, reports UK-based The Guardian.
Citing analysts, the report said that sectarian conflict in Pakistan has been fuelled by the long-going standoff between Sunni Saudi Arabia and predominantly Shia Iran.
Both countries have been accused of supporting their own favoured militant groups in Pakistan, where the Shia minority has been the target of relentless attacks, says The Guardian.
Pakistan declined to join the Saudi-led military campaign in Yemen against Shia Houthi rebels in 2015 despite relentless pressure.
But now the government's plan to allow Sharif, one of the most popular army chiefs in the country's history, to head the IMAFT has triggered widespread criticism on social media.
Shia political group Majlis Wahdat-e-Muslimeen has urged Sharif to turn it down while hardline Sunni groups like the banned Ahle Sunnat Wal Jamaat said they fully support it.
“But there is a question of how far IMAFT can be a non-partisan force.
“At the moment it appears to be dominated by conservative Arab kingdoms so Iran, Iraq and Syria will not welcome it,” The Guardian report quoted Pakistani defence analyst Hasan Askari Rizvi.
He cautioned against Pakistan being dragged into conflicts at the behest of others.
General Sharif has been highly lauded in his country for the crackdown on the Taliban leading to a substantial decline in violence.
During his term, the army ran a successful public relations campaign contrasting Sharif with the civilian leaders, who are widely viewed as corrupt in Pakistan.
Sharif retired in November last year amid speculations that he would be given an extension or promoted as a field marshal.