By Maria Golovnina
ISLAMABAD (Reuters) - Pakistan is to release former Afghan Taliban second-in-command Mullah Abdul Ghani Baradar on Saturday, yielding to years of calls from Afghanistan to free a man who it hopes could play a pivotal role in bringing peace to Pakistan's neighbour.
The United States and Afghanistan have long pressed Pakistan to free Baradar, a figure they believe could tempt moderate Taliban leaders to come to the negotiating table as U.S.-led troops prepare to leave Afghanistan at the end of next year.
The Pakistani Foreign Ministry said in a statement that Baradar, captured in Pakistan in 2010, would be freed "in order to further facilitate the Afghan reconciliation process".
Pakistani sources said he would probably be sent to Saudi Arabia or Turkey as part of that process, but Pakistani government officials would not confirm it.
Afghanistan is trying to inject life into its attempts to negotiate an end to the Islamist Taliban insurgency as most NATO combat troops prepare to pull out by the end of 2014, leaving the country to handle its own security.
Baradar was once a close friend of the reclusive Taliban leader, Mullah Mohammad Omar, who gave him his nom de guerre, "Baradar" or "brother".
Even before his detention, Baradar was known as a pragmatic and level-headed operator who had once reached out to Kabul to seek a peace settlement, according to Afghan officials.
But critics say his years in Pakistani detention may have eroded his sway over the fast evolving insurgency, and there are doubts over whether Mullah Omar would agree to talk to his former protégé in the first place.
After the 2001 invasion of Afghanistan by U.S.-led forces, Baradar emerged as the main day-to-day commander responsible for leading the campaign against them, planning offensives and bomb attacks.
Later, he secretly tried to explore the possibility of peace with Kabul, holding two meetings with Karzai's late brother in Kandahar, Afghan officials said. He was eventually captured in a joint CIA-Pakistani intelligence operation in Karachi.
(Reporting By Maria Golovnina; Editing by Kevin Liffey)