But companies have been slow to pony up money, which Lavin attributed to factors ranging from the global economic downturn to sponsorship at the Beijing Olympics just last year.

• 雷文凯认为，这里有几方面的原因，比如全球经济低迷、去年的北京奥运会上有过赞助等等。上海世博会将于明年5月开幕。