The 15th trade fair of Organization of Islamic Cooperation (OIC)'s Member States was concluded here today, which was held under the sponsorship of Custodian of the Two Holy Mosques King Salman bin Abdulaziz Al Saud, and was inaugurated by Prince Faisal bin Bandar bin Abdulaziz, Governor of Riyadh region. The fair was held with participation of 39 Islamic countries.