Potter film conjures up top slot

Daniel Radcliffe (left) is back as Harry in the latest Potter adventure

Harry Potter and the Half-Blood Prince, the sixth instalment in the boy wizard series, has debuted at the top of the North American box office.

The movie has raked in $159.6m (£96.7m) since it opened on Wednesday, according to early estimates.

The Half-Blood Prince beat the opening figures for The Order of the Phoenix, which was released in 2007 and took $139.7m (£84.6m) in its opening week.

Ice Age: Dawn of the Dinosaurs held steady at number two.

The third film in the animated series took $17.7m (£10.7m) over the weekend.

The Transformers sequel, Revenge of the Fallen, is at number three.

US AND CANADA BOX OFFICE 1. Harry Potter and the Half-Blood Prince - $79.5m 2. Ice Age: Dawn of the Dinosaurs - $17.7m 3. Transformers: Revenge of the Fallen - $13.7m 4. Bruno - $8.41m 5. The Hangover - $8.3m Source: Hollywood.com (formerly Media by Numbers)

Sacha Baron Cohen's latest film, Bruno, dropped into fourth place following its debut at number one last week, with takings of $8.4m (£5m) over the weekend.

The mock documentary made over $30m (£18m) in its first week.

Romantic comedy 500 Days of Summer - starring Zooey Deschanel and Joseph Gordon-Levitt - entered the chart at number 12, despite a limited release in just 27 cinemas.