The release of the film preceded the final book about Harry Potter

The Order of the Phoenix generated an estimated $77.4m (�38m) in three days, and has earned about $140m (�68.8m) since it opened last Wednesday.

It took more in five days than each of the first three Potter movies did in their opening weeks, Warner Bros said.

Last week's chart-topper, Transformers, dropped to number two.

It has now taken a total of $223m (�109.5m), becoming the highest-grossing film in the career of director Michael Bay.

It beat his previous record of $201m (�98.8m) for Armageddon in 1998.

Disney movie Ratatouille fell one place to number three, while the Bruce Willis adventure Live Free or Die Hard, released in the UK as Die Hard 4.0, also dropped one, to number four.

NORTH AMERICAN BOX OFFICE 1. Harry Potter and the Order of the Phoenix ($77.4m) 2. Transformers ($36m) 3. Ratatouille ($18m, pictured) 4. Live Free or Die Hard ($10.8m) 5. License to Wed ($7.4m) 6. 1408 ($5.0m) 7. Evan Almighty ($4.9m) 8. Knocked Up ($3.6m) 9. Sicko ($2.6m) 10. Ocean's Thirteen ($1.9m) Source: Media by Numbers

Completing the top five was License to Wed, a romantic comedy which slipped one place as well.

There were no other new entries in this week's top 10.

The only other large-scale release made its debut at number 12 - horror film Captivity, which featured former 24 star Elisha Cuthbert as a model who was abducted and tortured.

Warner Bros said it had "certainly turned out to be the right decision" to release Harry Potter and the Order of the Phoenix last Wednesday, rather than letting it debut on Friday, as happens with most films.

"We're in the middle of summer, and we just said why not, because kids are out of school," the studio's head of distribution, Dan Fellman, told the Associated Press.

This Saturday sees the publication of the seventh and final book in JK Rowling's series, Harry Potter and the Deathly Hallows.