Rehman made last ditch efforts to convince Hussain and leaders of the other four component parties of the MMA to delay the decision to resign, but in vain, Daily Times reported.
According to Pakistan, India will violate the Indus Water Treaty by constructing a hydropower project on Chenab.
Bugti, former chief minister of Balochistan and head of his tribe, was killed in 2006 in a military operation ordered by Musharraf who was president and army chief at the time.
PTI spokesman Fawad Chaudhry said that they have the required numbers to form government.