Pakistan has signed an agreement for purchase of gas from Tehran under the proposed Iran-Pakistan-India pipeline, Petroleum Minister Dr Asim Hussain said on Wednesday. Pakistan is working on several projects to meet its rising gas demands, including a multi-billion dollar gas pipeline project that will pump natural gas from Iran. The country sorely needs energy to feed shortfalls in its power sector and has said it plans to secure LNG by mid-2012 , but experts said without existing terminals it may have difficulty doing so.