Nov. 21 (Bloomberg) -- Dubai ruler Sheikh Mohammed Bin Rashid Al-Maktoum tightened his family’s control of the emirate’s largest holding company, the Investment Corporation of Dubai.

A decree posted Nov. 19 on Sheikh Mohammed’s Web site listed six members of a new board. It didn’t include Mohammad al-Gergawi, Sultan Ahmed Bin Sulayem or Mohammed Ali Alabbar, three key business aides of the Dubai ruler who are currently named as directors on the investment body’s Web site.

Al-Gergawi, Bin Sulayem and Alabbar were at the forefront of a debt-driven building boom in Dubai that collapsed after the onset of the global financial crisis last year. Dubai, the second-biggest of seven states that make up the United Arab Emirates, and its government-owned companies borrowed $80 billion to finance the emirate’s transformation into a financial and tourist hub before credit markets froze.

Sheikh Mohammed will continue to chair the board of the investment body. His son, Crown Prince Sheikh Hamdan bin Mohammed bin Rashid Al-Maktoum, is the deputy chairman. Other members of the board, which will serve for three years, include Sheikh Ahmed bin Saeed Al-Maktoum, Sheikh Mohammed’s uncle, who is chairman of Emirates Airline.

‘Monopolization of Power’

“We’re seeing a monopolization of power by the ruler’s court,” said Christopher Davidson, a Middle Eastern studies professor at Durham University in the U.K. and author of the 2008 book “Dubai: The Vulnerability of Success.” “Sheikh Mohammed entrusted a section of the Dubai economy to these powerful captains of industry and he feels they let him down.”

Bin Sulayem is chairman of Dubai World, a state-run holding company that controls port operator DP World Ltd., property developer Nakheel PJSC and asset management firm Istithmar World PJSC. It has about $59 billion of debt and other liabilities. Al-Gergawi is chairman of Dubai Holding, which owns developers including Dubai Properties, Tatweer and Sama Dubai. Alabbar is chairman of Emaar Properties PJSC.

The reshuffle of the investment holding company follows a move earlier this month by Sheikh Mohammed to take direct control of the emirate’s planning and supervisory agency, as the government tightens scrutiny of indebted state companies.

The agency, known as the Executive Office, set up in 2006, will now operate under Sheikh Mohammed’s court, according to a Nov. 4 statement.

The Investment Corporation of Dubai will take control of Dubai Duty Free under the Nov. 19 decree. It already controls assets including Emaar, the U.A.E.’s biggest developer, Emirates Airline, Emirates NBD bank and Dubai Aluminium Co., the largest smelter in the Middle East.

To contact the reporter on this story: Henry Meyer in Dubai at hmeyer4@bloomberg.net.

Last Updated: November 20, 2009 16:51 EST