Led by the blockbuster Batman sequel The Dark Knight, US-Canadian weekend ticket sales since May 2 are running just ahead of last summer, up 1.2 percent, according to box office tracking service Media By Numbers.

But with the number of actual admissions down nearly 3 percent from a year ago, the gain in revenues is fueled mostly by higher ticket prices.

With no other huge hits on the horizon before the US Labour Day holiday on Sept. 1, the 2008 vacation season will likely draw to a close at about the same level as last year's summer tally, which crossed the $4 billion threshold for the first time, box office analysts said.

Brandon Gray of the Web site Box Office Mojo said Hollywood suffered in the second half of summer from a mediocre film slate propped up almost entirely by the record-breaking strength of The Dark Knight, now closing in on $500 million.

"If ‘Dark Knight' failed to perform way above expectations, this would have been a decidedly down summer," Gray said.

Paul Dergarabedian of Media By Numbers agreed, saying Hollywood was hard-pressed to repeat the success of last year, which was anchored by "threequels" Spider-Man 3, Shrek the Third and Pirates of the Caribbean: At World's End.

Games And Gasoline

Dergarabedian said keen interest in the Beijing Olympics may also have dampened movie going in August.

Economic woes and high gas prices cut both ways at box offices as cash-strapped families sought relatively cheap entertainment in the form of movies, but were more choosy about which films to see.

"They may not hesitate for one second to spend 10 bucks on a movie ticket to go see The Dark Knight, but some of these other films, they may say, 'Oh, I'm going to wait,' or 'I'm going to be a little bit more careful with my spending.'"

Comic book adventures with a twist proved to be the hot ticket of summer 2008, accounting for at least three of the top four films and nearly $1.5 billion in revenues.

The Dark Knight, gained much of its notice from the menacingly edgy performance of Heath Ledger as the villainous joker, his last completed film role before he died of an accidental overdose of prescription drugs.

Likewise, Iron Man kicked off the summer season in robust fashion with Robert Downey Jr. winning praise for his role as a wealthy weapons executive who invents a high-tech armor suit.

Those films have been the two highest-grossing titles of the summer, amassing over $471 million and $317 million respectively in North American receipts so far.

Ranked fourth, with $225 million, was Hancock, starring Will Smith as a hung-over, often reckless superhero.

Even the summer's No. 3 movie, Indiana Jones and the Kingdom of the Crystal Skull, which grossed $315 million, could be classified as a superhero movie of sorts.

The Incredible Hulk was No. 10 with $134 million, while Hellboy 2: The Golden Army, landed at No. 24 with nearly $75 million. Other bright spots included chick flick Sex and the City and the animated hits Wall-E and Kung Fu Panda.

With the exception of Dark Knight and the musical Mamma Mia! , the box office had cooled considerably by mid-July. Of the 16 summer weekends so far, nine were down year-to-year in overall ticket sales.