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DUBAI, March 19 (Reuters) - One of Dubai's leading real estate tycoons will take charge of Dubai Holding, the investment vehicle of the emirate's ruler which has a $35 billion portfolio of assets in over 20 countries, the Dubai government said on Sunday.

Abdulla al-Habbai was chosen as chairman of the investment conglomerate by Dubai ruler Sheikh Mohammed bin Rashid al-Maktoum, the government said in a brief statement.

Habbai will remain chairman of Meraas Holding, a big real estate developer which is controlled by Sheikh Mohammed and in the last few years has played an increasingly important role in expanding Dubai's luxury real estate and tourism sectors.

Among its projects, Meraas launched its DXB Entertainments DXBE.DU subsidiary, which has built a theme park and water park complex on the outskirts of the city to try to attract hundreds of thousands of additional tourists to Dubai.

Dubai Holding's previous chairman, Mohammed Abdullah al-Gergawi, resigned last month after heading the company since it was founded in 2004. Gergawi said he wanted to work full-time for the United Arab Emirates government, where he is minister of cabinet affairs and in charge of strategy development.

Within the emirate, Dubai Holding operates a wide range of business parks in addition to assets in tourism, telecommunications and other sectors.

(Reporting by Andrew Torchia; Editing by Keith Weir) ((Sami.Aboudi@thomsonreuters.com; +97143918301;))