Muslim leaders gather Thursday for a rare summit in Pakistan designed to increase trade and investment but likely to be overshadowed by the Gaza conflict.

Iranian President Mahmoud Ahmadinejad, Egyptian leader Mohammed Morsi and Turkish Prime Minister Recep Tayyip Erdogan, key players in West Asia, are scheduled to attend the Developing Eight (D8) summit.

The D8 groups Bangladesh, Egypt, Indonesia, Iran, Malaysia, Nigeria, Pakistan and Turkey.

Nigerian leader Goodluck Jonathan arrived in Islamabad on Wednesday. Indonesian President Susilo Bambang Yudhoyono is also due to attend.

The summit will mark the first visit by an Egyptian president to Pakistan in four decades and the first by a Nigerian in 28 years.