Under the patronage of the Custodian of the Two Holy Mosques, King Abdullah bin Abdulaziz Al Saud, the 3rd International GCC Forum and Exhibition of Environment and Sustainable Development will be held here later today. The third scientific session of the three-day Forum will be chaired tomorrow by Prince Abdulaziz bin Salman bin Abdulaziz, Assistant Minister of Petroleum and Mineral Resources for Petroleum Affairs.