UPDATE 1-New Harry Potter movie sets world opening record

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LOS ANGELES, July 16 (Reuters) - The latest "Harry Potter" movie cast a $104 million spell over worldwide box offices during its first day in theaters, setting a new record for the boy wizard, distributor Warner Bros Pictures said on Thursday.

"Harry Potter and the Half-Blood Prince," the sixth in the film series based on the popular books by J.K. Rowling, grossed $58.18 million in North America and $45.85 million overseas on Wednesday, the Time Warner Inc-owned (TWX.N) studio said.

The U.S.-Canadian tally, which includes a record $22.2 million from midnight showings, marks the second-biggest Wednesday opening domestically.

Only last month's "Transformers: Revenge of the Fallen" scored a bigger midweek first-day gross, with $62 million in domestic ticket sales on Wednesday June 24, according to Paul Dergarabedian, box office analyst for Hollywood.com.

The latest "Harry Potter" also ranks as the fourth-highest single-day gross for a film release in North America, behind No. 1 "Dark Knight" ($67.1 million), No. 2 "Transformers: Revenge," and third-place "Spider-Man 3" ($59.8 million).

"Quite simply, we owe this record-breaking opening to the remarkable fans who have stood by us and who stood in line to be among the first to see 'Harry Potter and the Half-Blood Prince,'" Warner Bros President and Chief Operating Officer Alan Horn said in a statement.

Said Dergarabedian: "This is a tremendous opening. It's in the box office stratosphere."

The previous "Harry Potter" movie, "Harry Potter and the Order of the Phoenix," also opened on a Wednesday last year with first-day domestic receipts of $44.2 million. That film went on to gross $937 million worldwide.

The first five films in the franchise, one of the most lucrative in Hollywood history, have so far taken in about $4.5 billion collectively at the global box office. (Reporting by Jill Serjeant and Steve Gorman; Editing by Doina Chiacu and Todd Eastham)