United Nations Secretary General Ban Ki-moon said: "Since May of this year, all around the world, people have been talking about a remarkable, even historic event."

He told the forum that Shanghai had "secured its reputation as one of the world's most cosmopolitan cities".

"Along the way, it has completed a transformation many years in the making," he said.

Dancers perform in the closing ceremony of the Expo, wearing hats shaped as different pavilions. [Photo/Xinhua]

At the closing ceremony on Sunday night in the shell-shaped Expo Cultural Center, Wen officially declared the closure of the Expo.

The flag of the International Exhibitions Bureau was lowered and handed over to Milan, Italy, the host city of the next Universal Expo in 2015.

The ceremony was followed by a joyful and heart-warming gala that saw celebrities, including Hong Kong action film star Jackie Chan, singing together with visually impaired children.

Amid a chorus of tenors, performers wearing costumes in the shape of pavilions provided a reminder of the memorable exhibitions, which celebrated human endeavor in making the planet a more livable place.

The gala also highlighted the spirit of voluntarism, which saw 600,000 volunteers, mainly college students, work in the Expo Garden while millions of others served around the city.

Staff of pavilions from all around the world also showed their talent by joining a rendition of world-famous songs in English, French, Russian, Spanish, Arabic, and Chinese to celebrate a global community of cultural diversity.

The 73 million who managed to get to the event surpassed the previous record of 64.21 million visitors who attended the 1970 fair in Osaka, Japan.

The 5.2 square kilometer Expo zone handled an average of 370,000 visitors daily, and a record 1.03 million on Oct 16.

The next International Expo, in 2012, will be in the South Korean port city of Yeosu, with a similar theme of "Green Growth, Blue Economy," or marine-based sustainability.

After that the Expo will move to the Italian city of Milan in 2015, for the Universal Expo with a focus on food safety and security.

Wu Yiyao contributed to this story.