Update Wed. July 29, 3:30 PM PST: In an exclusive statement to Access Hollywood, Rachel Lefevre says she's "stunned" by Summit's decision to re-cast the role.

She continued, “I was fully committed to the ‘Twilight’ saga, and to the portrayal of Victoria.  I turned down several other film opportunities and, in accordance with my contractual rights, accepted only roles that would involve very short shooting schedules. My commitment to ‘Barney’s Version’ is only ten days. Summit picked up my option for ‘Eclipse.’ Although the production schedule for ‘Eclipse’ is over three months long, Summit said they had a conflict during those ten days and would not accommodate me. Given the length of filming for ‘Eclipse,’ never did I fathom I would lose the role over a 10 day overlap. I was happy with my contract with Summit and was fully prepared to continue to honor it. Summit chose simply to recast the part.”

This would support this writer's original theory, based on her comments on the set in May, that Lefevre wouldn't take any other role that would conflict with her finishing her character's trilogy in "The Twilight Saga: Eclipse".  More as it develops.

Original Post Tues. July 28, 10:45 PM PST:  In a major surprise to hardcore "Twilight" fans, the pivotal franchise role of Victoria has been recast. 

The part had been portrayed by the relatively unknown Rachelle Lefevre in both "Twilight" and the upcoming "The Twilight Saga: New Moon." Tonight, however, Summit Entertainment announced Bryce Dallas Howard would take over the role in the upcoming third installment, "The Twilight Saga: Eclipse," which is scheduled to begin shooting at the end of the summer. 

The villainous vampire first appeared in "Twilight" as a foil for the Cullens and Edward (Robert Pattinson) in particular. Victoria also appears in "New Moon," but is a central part of the conflict in "Eclipse" where she meets a grotesque end many fans can't wait to see on the big screen.

The studio explained the departure in a press releasing noting Lefevre "will not continue in the role due to scheduling conflicts with another commitment the actor has made." This is intriguing as the only picture Lefevre is publicly attached to is the indie "Barney's Shaft" with Dustin Hoffman and Paul Giamatti. It's hard to imagine any actress turning down the opportunity to finish out a role she appeared in two previous films unless the names Steve Spielberg, Peter Jackson, James Cameron or Clint Eastwood are involved.  The news is even more peculiar considering how faithful Lefevre has been to the "Twilight" fanbase appearing at countless events on behalf of the franchise since the first film exploded at theaters last November.  Just this past week Lefevre was on hand for some of the publicity events at San Diego Comic-Con.  On the other hand, she did not appear on the Hall H panel with Pattinson, Kristen Stewart, Taylor Lautner, Ashley Greene and director Chris Weitz as she had the previous year.

HitFix spoke to Lefevre on the set of "New Moon" in Vancouver at the beginning of May and not returning seemed out of the question if she had a conflict.  When asked about what she was doing in between the two films, Lefevre said, "I have a couple of things sort of in the mix right now that it looks like I’m going to get to do. One in between this and “Eclipse” but it’s a scheduling thing and so nothing is confirmed yet because you have to be available for the third movie."

As of 10:45 PM PST, Lefevre had not commented on her official twitter at twitter.com/RachelleLefevre.  In fact, the normally busy tweeter hasn't commented once over the past three days.

The addition of Howard, however, only increases the stature of the franchise which brought on Michael Sheen and Dakota Fanning for "New Moon."  Howard was most recently seen in "Terminator: Salvation," but is known for her roles in "The Lady in the Water" and "The Village."

Replacing actors in franchises is becoming a bit too common these days.  Maggie Gyllenhaal stepped in for Katie Holmes in "The Dark Knight" and Don Cheadle did the same for Terrence Howard in the upcoming "Iron Man 2."  Both those situations had little to do with "scheduling conflicts" and money or personality issues.

Look for more on this story as it develops on HitFix.

"The Twilight Saga: Eclipse" is already scheduled for release on June 30, 2010.