The shape-shifting robots in Transformers morphed into last weekend's U.S. box office leaders. The DreamWorks-Paramount take on the popular line of Hasbro toys took in $67.6 million in ticket sales in its first weekend, according to July 8 studio estimates.

This brings its domestic total to $152.5 million, counting July 2 preview screenings. If those figures hold up, it would give Transformers the largest first-week revenue in history for a non-sequel, topping Spider-Man's $151.6 million total in 2002.

Rob Moore, Paramount's head of worldwide marketing and distribution, said director Michael Bay added striking special effects to the already potent lure of the Transformers brand - which debuted in the 1980s with toys, a TV show and an animated movie. The film also took in $93.6 million in 23 other countries where it's been showing since June 28.

Overall domestic box office figures plunged, however, with the top 12 movies taking in $161.5 million - down 23 percent from the same weekend in 2006. "The good news is we've got another big one right around the corner with Harry Potter and the Order of the Phoenix, said Paul Dergarabedian, president of box-office tracker Media By Numbers. "We should be looking at a strong midsummer boost that'll hopefully carry through to the end of summer."