Bangladesh is going to sign the first Preferential Trade Agreement (PTA) with which country?

This is going to be Bangladesh's first preferential trade agreement with SAARC friendly country Bhutan. The Ministry of Law has completed the vetting of the agreement. Now the National Board of Revenue (NBR) is analyzing their views. All preparations have been made to complete the contract by the end of August or the first week of September. The Ministry of Commerce considers this to be a historic agreement and a milestone in Bangladesh's trade and commerce. No free trade or preferential trade agreement has been signed with any country before.
Source- Daily Janakantha