Adia fund worth less than $800 bln - Abu Dhabi ruler

DUBAI, June 29 (Reuters) - Estimates placing the size of Abu Dhabi's sovereign wealth fund at $800 billion are exaggerated, Sheikh Khalifa bin Zayed al-Nahayan, ruler of Abu Dhabi and president of the United Arab Emirates, was quoted as saying.

Speaking to Lebanon's al-Nahar newspaper over the weekend, Sheikh Khalifa also said the sovereign wealth funds -- of which the Abu Dhabi Investment Authority, or Adia, is the world's biggest -- made decisions along economic not political lines.

"The estimations you have mentioned are exaggerated and they do not reflect the truth and the size of Emirati investments abroad," he said, when asked whether the value of the funds' investments abroad exceeded $800 billion.

"The sovereign funds which you have referred to operate according to economic principles, not political considerations."

Swollen by windfall oil revenues and foreign currency reserves, global sovereign wealth funds hold assets of between $1.9 trillion and $2.9 trillion, the U.S. Treasury Department estimates.

Gulf-based funds such as Adia or the Kuwait Investment Authority have played key roles in capital-raising efforts by Western banks suffering from writedowns stemming from the credit crisis. They have also stoked concern that some Western countries could lose control over key industries.

The UAE is the world's fifth-largest oil exporter and Abu Dhabi, home to most of the country's reserves, has been using part of its record oil revenues to diversify its economy and invest abroad. (Reporting by Thomas Atkins; Editing by Alan Raybould)