UPDATE 1-Singapore's Changi to run central Vietnam airport

(Adds details of agreement)

SINGAPORE, Feb 26 (Reuters) - Singapore's state-owned Changi Airports International said it would invest in and operate an airport in the popular tourist area of Hue in Vietnam, which is opening airport management to foreign investment.

The deal to manage Phu Bai International Airport in the central province of Thua Thien-Hue will involve new investment, Changi said in a statement on Tuesday, but did not say how much.

Changi manages Singapore's international airport and has been involved in development of more than 40 airports globally.

As many as 5 million foreign tourists are expected to visit Vietnam this year, up nearly 20 percent on a year ago.

Details of future operation with Changi, including the investment value, would be further discussed, a Vietnamese aviation official said at the signing ceremony in Hanoi.

Vietnam, which forecast air passenger traffic to more than double to 32.4 million people by 2020 from 14.5 million a year now, has been opening up its aviation sector to foreign investment after joining the World Trade Organisation last year.

In mid-2007 the Vietnamese government sold a 30 percent stake in Pacific Airlines, the country's second-largest after Vietnam Airlines, to Qantas Airways Ltd (QAN.AX).

Last November it licensed VietJet Air, its first fully private airlines, and said more private carriers would become operational in the next five years to meet demand.

National carrier Vietnam Airlines said last month it would hire an international consultant soon to advise on its initial public offering and could sell up to 20 percent of its shares to three foreign strategic investors. (Reporting by Kevin Lim in Singapore and Ho Binh Minh in Hanoi; Editing by Louise Heavens and Lincoln Feast)