DOHA (AFP) - Muslims should take advantage of the global financial crisis to build an economic system compatible with Islamic principles, influential Imam Sheikh Yusuf al-Qaradawi said on Sunday. "The collapse of the capitalist system based on usury and paper and not on goods traded on the market is proof that it is in crisis and shows that Islamic economic philosophy is holding up," said the Egyptian-born, Qatar-based Imam. "The Western system has collapsed and we have a complete economic philosophy as well as spiritual strength," he said at Sunday's opening of a conference on Jerusalem. "All riches are ours... the Islamic nation has all or nearly all the oil and we have an economic philosophy that no one else has," Qaradawi said. He urged Muslims to "profit from the crisis to bring about the triumph of the (Islamic) nation, which holds the spiritual and material resources for victory." The sixth conference on Jerusalem is being attended by around 300 people representing political parties as well as Muslim and Christian NGOs, from various countries. It is staged by Al-Quds (Jerusalem) International Institution, which is dedicated to the conservation of the holy city and its sacred places. Participants include Khaled Meshaal, exiled head of the Palestinian Islamist movement Hamas, and Ali Akbar Velayati, a top adviser to Iranian spiritual leader Ali Khamenei. The three-day conference will look at ways of protecting Jerusalem and its holy sites, which participants believe are threatened by Israel.