Iranian President Mahmoud Ahmadinejad said today that development of Iran needs efforts, cooperation and convergence, reported the official Iranian news agency IRNA . President Ahmadinejad was addressing the inaugural ceremony of Iran's biggest gray cement factory in the central city of Zarandiyeh. "All parts of Iran should be developed. We should strive to produce cost efficient products and reduce costs," he said. He added Iran should become a constructor of cement factories on international scene, saying, "Certain countries have called on Iran to build cement factories for them. It will be an appropriate opportunity to promote the country's industries." "Investors should pay necessary attention to existing opportunities. They should raise production to its highest level and pay attention to overseas ventures," he said. -- SPA