ORLANDO (REUTERS) - Universal Orlando kicks off previews on Wednesday of its much anticipated Diagon Alley, a second Harry Potter-themed attraction that is expected provide a boost for the park's revenues and for tourism in central Florida.

Universal has yet to fix a date for the opening of Diagon Alley this summer, but theme park experts predict a major bump in tourism based on the response to the original, a recreation of Hogsmeade Village, which required staggered entry times long after the June 2010 grand opening to control crowds. "There are heightened expectations for this expansion," said Richmond-based theme park consultant John Gerner of Leisure Business Advisors.

Universal did not respond to inquiries about company attendance expectations.

In the month after the original Harry Potter attraction opened, bed tax revenue from hotel guests in Orange County jumped 21 per cent over the previous year. "It certainly appeared to be a correlation to the Harry Potter opening," said Peggy McGarrity, deputy county comptroller, who added that double-digit increases became standard thereafter.

Universal and the Harry Potter franchise are being promoted all week on the Tonight Show with Jimmy Fallon. The network and resort are both owned by Comcast. "It's unusual you would have a national show like the Tonight Show to promote this. That's an indication they are doing everything they can," Gerner said.

Universal is promising a red carpet event to unveil the park on Wednesday night with some of the film's stars but is not saying which ones.

Diagon Alley recreates the wizarding business district in London described in J. K. Rowling's book and movie series.

The attraction will be geared in large part toward eateries and souvenir shops, both of which have been bottlenecks in the Hogsmeade Village, home to the wizard school Hogwarts.

Gerner said popular themed attractions can double their ticket price revenue from in-park sales.

To visit both sections of the Wizarding World of Harry Potter, guests will have to buy a more expensive two-park pass because Hogsmeade and Diagon Alley were built in separate Universal parks. The attractions are connected by a train featured in books and movies which is a themed ride in itself.

Gerner said this is the first time a resort has found a way to seamlessly connect two separately ticketed parks to drive up ticket sales.