The president of the United Arab Emirates, who oversaw the transformation of a cluster of tiny desert Persian Gulf sheikdoms into a leading oil and business hub with skyscrapers and sprawling shopping malls, has died. He was 86.

Sheik Zayed bin Sultan Al Nahyan (search), one of the richest rulers in the world according to Forbes magazine, forged close ties with the United States and the West during his rule of the country, which is the world's ninth largest oil producer.

Sheik Zayed was expected to be succeeded by his eldest son, Sheik Khalifa bin Zayed Al Nahyan (search). The leaders of the seven emirates that make up the country will appoint the new president within 30 days.

In the meantime, the prime minister — Sheik Maktoum bin Rashid Al Maktoum (search), a close relative of Sheik Zayed — will serve as acting president. During the president's illness, Sheik Maktoum has been the public face of the Emirates.

Abu Dhabi TV interrupted regular broadcasting to break the news of the death of the man who led the United Arab Emirates since its independence from Britain in 1971. He had been ailing for several years, was largely out of public eye and did not attend Arab summits. He had a kidney transplant in August 2000.

The announcement was followed by an Islamic cleric appearing on TV reading verses from the Quran.

The official Emirates news agency, WAM, released its own announcement, lauding him as "the leader of the nation and the builder of its civilization."

Based on Islamic tradition, Sheik Zayed will be buried as soon as possible, most likely Wednesday.

Sheik Zayed led the unification of the seven tiny emirates on the eastern edge of the Arabian Peninsula — once a backwater relegated to fishing from traditional dhow boats and diving for pearls in the Gulf waters.

He became the ruler of Abu Dhabi (search), the largest emirate, in 1966, four years after the emirate first began exporting the oil it had just discovered off its shores. At the time, Abu Dhabi city was a collection of huts clustered around the ruler's fort.

Today, the country — with a population of around 850,000 Emiratis and 2.6 million foreign expatriates and workers — is a leading member of the Organization of Petroleum Exporting Countries (search), the world's ninth leading producer and fifth-largest exporter.

Billions of oil dollars were invested to make Abu Dhabi an oasis of high-rises, parks, fountains, manicured flower beds, restaurants and a wildlife island. The country has also sought to diversity the economy, becoming a center for banking and finance.

Dubai (search), the second largest emirate, now gets most of its revenues from trade.

Following the Sept. 11 attacks on the United States, the Emirates were among several Arab countries pressured by Washington to reform their financial sectors, which had been linked to the funneling of funds to international terrorist groups like Al Qaeda.

The Al Nahyan family held more than three-quarters of the stock in the bank BCCI (search), which in the early 1990s was at the center of one of the world's biggest bank frauds.

Severe losses in securities trading and phony loans and insider stock trades led to the collapse of the bank, which had offices in 69 nations. Twelve top executives from the bank were convicted and forced to pay some $9.13 billion in restitution to the Abu Dhabi government.

While the Emirates' wealth grew, Sheik Zayed was known for seeking to maintain the traditions of his Bedouin (search) roots and the personal rule of a tribal sheik.

He would hold a daily majlis (search), or open court, to let citizens air their concerns. He would try to attend weddings of ordinary citizens whenever invited and stroll the tree-lined streets accompanied only by two bodyguards.

He was a passionate falconer, with about 500 falcons trained for hunting and, before his health began to fail, would spend weeks on hunts in Pakistan and Morocco.

Sheik Zayed was married many times, though he adhered to Islamic law limiting a man to four wives at any one time. He had more than 21 sons and an undivulged number of daughters.

His eldest son, Sheik Khalifa, who was born in 1948. Though lacking his father's charisma and reputation, he is a powerful figure in the country, holding the post of deputy commander of the armed forces and, as chairman of Abu Dhabi's executive council, handling most of the emirate's day-to-day affairs.

Condolences poured in from around the Gulf and Arab world for Sheik Zayed. Jordan's King Abdullah II declared a 40-day period of mourning. During his rule, Sheik Zayed deposited hundreds of millions of dollars into Jordan's Central Bank to boost the country's economy.