By Lisa Richwine
LOS ANGELES (Reuters) - British boy wizard Harry Potter makes his final return to theaters this week and may bring enough box office magic to score the biggest opening weekend ever for the hugely successful series.
Box office estimates for opening weekend ticket sales of "Harry Potter and the Deathly Hallows -- Part 2" in the United States and Canada range from $125 million to $150 million, industry watchers said, putting it in league with the highest-grossing film debuts ever.
The record for best weekend opening belongs to 2008 Batman movie, "The Dark Knight," which collected $158.4 million in its initial three-days.
"Deathly Hallows -- Part 2" is the eighth and final film in the franchise. The Warner Bros. films have generated $6.4 billion in ticket sales since the first movie a decade ago, plus billions more from DVDs and merchandise.
Loyal fans eager to say farewell are expected to drive big numbers for the last installment, industry experts said.
"Harry Potter is remarkably consistent, hitting blockbuster levels each time out. This will be the culmination of everything, this long, nearly 10-year investment," said Brandon Gray, president of industry tracker boxofficemojo.com.
Initial ticket sales will "likely be the highest grossing opening weekend of the series," Gray said.
People with no prior interest in "Harry Potter" will go to the finale "simply because it is the end of an era," said Paul Dergarabedian, who heads up Hollywood.com Box Office. The film's marketing slogan -- "It All Ends" -- stresses that point.
The final film is the first "Harry Potter" offered in 3D, which should help boost sales totals with its premium price. The movie also will be shown on large format IMAX screens.
"Deathly Hallows -- Part 2" opens in some countries on Wednesday and in the key British and U.S. markets on Friday.
Warner Bros., a unit of Time Warner Inc, touted the movie's pent-up demand even before the film opened. Advance ticket sales reached more than $32 million, a pre-opening record, with many midnight and first-day show times sold out, the company said.
"Deathly Hallows - Part 1" racked up big sales of $125 million domestically on its opening weekend last November, showing the story still appeals widely after a decade. The new film should beat that total, Dergarabedian said.
The final film "has so much going for it. There's a mystique. There's a fervor," he said.
(Reporting by Lisa Richwine; Editing by Bob Tourtellotte)