LOS ANGELES — The intergalactic misfits of "Guardians of the Galaxy" are the summer's box-office superheroes.
Marvel's cosmic romp topped the Labor Day box office with a three-day take of $22 million — its third time in first place since its release five weeks ago, according to studio estimates Monday. With North American ticket sales of more than $280 million so far, "Guardians" is also the summer's — and the year's — top-grossing film to date domestically.
Still, summer box-office totals are down almost 15 percent from last year, said Paul Dergarabedian, senior media analyst for box-office tracker Rentrak.
"This is the lowest summer since 2006 in terms of revenue," he said. "Before 'Guardians,' we were sitting on a 20 percent deficit compared to last year."
"Transformers: Age of Extinction," which opened in late June, also boosted the summer box office with $1 billion in global ticket sales. "Maleficent" was another hit, bringing in more than $230 million domestically.
"This was never expected to be a record-breaking summer," Dergarabedian said, "but it maybe came in under expectations."
The World Cup may have distracted moviegoers, he said. Also, the death of Paul Walker caused the seventh installment of "Fast & Furious" — which might have added around $200 million to the summer box office — to be postponed until next year.
Last summer broke box-office records with the success of "Iron Man 3," ''Star Trek," ''The Heat" and "Despicable Me 2." Next summer is expected to make history again with hotly anticipated releases including "Star Wars," ''Avengers: Age of Ultron" and Pixar's "Inside Out."
"Summer of 2014 is a transitional summer between two record-breaking years," Dergarabedian said.
The top movies over the lackluster Labor Day holiday were the same as the previous weekend. Paramount's "Teenage Mutant Ninja Turtles" followed "Guardians" with $15.7 million, while Warner Bros.' young-adult drama, "If I Stay" took third place with $11.6 million.
"We went out with a whimper," Dergarabedian said. "We wound up a very exasperating summer on a very quiet note."
Estimated ticket sales for Friday through Monday at U.S. and Canadian theaters, according to Rentrak. Where available, the latest international numbers (through Sunday) are also included. Final domestic figures will be released on Tuesday.
1. "Guardians of the Galaxy," $22.2 million ($19.7 million international).
2. "Teenage Mutant Ninja Turtles," $15.7 million ($13 million international).
3. "If I Stay," $11.6 million ($4.6 million international).
4. "Let's Be Cops," $10.5 million ($6.6 million international).
5. "As Above, So Below," $10.3 million ($1.4 million international).
6. "The November Man," $10.2 million.