DUBAI  - Dubai Holding, the investment vehicle of Dubai's ruler Sheikh Mohammed bin Rashid al-Maktoum, is weighing an initial public offering of business park operator TECOM Group, three sources told Reuters.

U.S. investment banks Morgan Stanley and Goldman Sachs and Swiss bank UBS  are close to securing a mandate for roles on the public share sale, said the sources, who declined to be named as the matter is not public.

TECOM Group and Dubai Holding did not immediately respond to a request for comment. Morgan Stanley and Goldman Sachs declined to comment.

One of the sources said banks were still pitching and may still join the syndicate of advisors.

"It will be a sizeable deal," said a second source aware of the transaction, adding the exact size will be determined after they have finalised the assets that will be injected into the listed vehicle.

Formerly known as TECOM Investments, TECOM Group which is a part of Dubai Holding, says it has a portfolio of 10 business parks where around 6,500 businesses employ a total workforce of 95,000.

The Dubai government last week announced plans to list 10 state-backed companies on its stock market as part of plans to boost activity on the local bourse. It also said it plans to set up a 2 billion dirhams ($545 million) market maker fund to encourage more private companies to list.

A spate of de-listings and an absence of big initial public offerings have put Dubai's stock market under pressure, raising questions over the future of one of the Gulf's major exchanges, launched two decades ago.

(Reporting by Hadeel Al Sayegh; Additional Reporting by Saeed Azhar; Editing by Toby Chopra) ((; +971566883310;))