Transformers: Dark of the Moon, which begins its assault Tuesday night, should pick up noticeably as the Fourth July holiday weekend gets underway in the United States.

The third Transformers film, which cost about $200 million to make, recorded the best opening-day gross of 2011. The film grossed $37.2 million on Wednesday in its first full day of play at U.S. and Canadian box offices compared to Pirates of the Caribbean: On Stranger Tides,

The number was higher compared to first Transformers, but 40 percent lower that its sequel Transformers: Revenge of the Fallen, which grossed $62 million in its first day.

Previously, Pirates of the Caribbean: On Stranger Tides, which is the fourth movie of the franchise, recorded the best opening day with $34.8 million, including $4.7 million in midnights, on a Friday.

Including the $5.5 million earned in Tuesday night sneaks, the Michael Bay tentpole has grossed $42.7 million in domestic theaters during its first two days, Reuters reported.

On Wednesday, the movie released in to a total of 4,000 theaters, including 2,800 3D sites. Roughly 60 percent of the ticket sales are coming from 3D theaters, including Imax runs, which have raked in a strong $3.3 million.

Tracking suggests Dark of the Moon will gross $150 million to $160 million through July 4th , which falls on a Monday. But the number is far less than the $214 million Revenge of the Fallen earned in its five-day debut in summer 2009.

Transformers is Paramount's biggest franchise, with the first two films grossing $1.54 billion. The last movie, Transformers: Revenge of the Fallen was the second highest grossing movie in 2009 but it drew negative reviews, and Bay himself has said that it wasn't his best effort.

Moon