Los Angeles ? The signs are everywhere that summer blockbuster season has ended.

The alien-invasion tale “Signs” climbed back to the No. 1 spot at the box office with a $14.4 million haul in its fourth weekend, while the espionage thriller “XXX,” the top film for the last two weekends, came in a close second with $13.7 million, according to studio estimates Sunday.

The weekend’s three new movies debuted weakly. Elizabeth Hurley and Matthew Perry’s romantic comedy “Serving Sara” was No. 6 with $6.1 million; the Wesley Snipes-Ving Rhames prison boxing drama “Undisputed” was No. 8 with $4.7 million; and Al Pacino’s Hollywood satire “Simone” came in at No. 9 with $4.1 million.

And the overall box office was down for the sixth straight weekend. The top 12 movies grossed $63.9 million, off 22 percent from the same weekend last year, when a stronger crop of holdover movies such as “American Pie 2” and “Rush Hour 2” led the way.

“Summer’s definitely over,” said Paul Dergarabedian, president of box-office tracker Exhibitor Relations. “The difference is the last six weeks of last summer were incredibly strong. This year, this group of films is not standing up to that level.”

The thinning film lineup has smoothed the way for smaller independent films.

The summer’s biggest sleeper hit, “My Big Fat Greek Wedding,” expanded to 1,329 theaters, up 269, and grossed $7.6 million to bring its total to $64 million. Nearly five months after its release, the film climbed to No. 4, its highest rank yet, up from sixth place last weekend.

In limited release, Robin Williams’ “One Hour Photo,” in which he plays a dreary photo clerk who dangerously obsesses on a family of customers, took in $315,000 at just seven theaters in five cities to average a whopping $45,000 per theater.

Jennifer Aniston’s “The Good Girl” expanded to 188 theaters in its third weekend and grossed $1.55 million for an impressive average of $8,245.

Hollywood is still on track to slightly edge last summer’s revenue record of about $3 billion from Memorial Day weekend through Labor Day, Dergarabedian said. But factoring in higher admission prices, summer 1999 remains the modern record holder for tickets sold, he said.

Estimated ticket sales for Friday through Sunday at North American theaters, according to Exhibitor Relations Co. Inc.:

1. “Signs,” $14.4 million.

2. “XXX,” $13.7 million.

3. “Spy Kids 2: The Island of Lost Dreams,” $7.8 million.

4. “My Big Fat Greek Wedding,” $7.6 million.

5. “Blue Crush,” $6.5 million.

6. “Serving Sara,” $6.1 million.

7. “Austin Powers in Goldmember,” $5.6 million.

8. “Undisputed,” $4.7 million.

9. “Simone,” $4.1 million.

10. “Blood Work,” $2.9 million.