L.A. Paving the Way for ‘Boulevard’ : Stage: The Shubert Theatre will be altered for Lloyd Webber musical, set to open here next October or November.

Look for the American premiere of Andrew Lloyd Webber’s new musical version of “Sunset Boulevard” to take place next October or November at the Shubert Theatre in Century City, following its world premiere in London on June 29--and also following major structural renovations at the Shubert that will alter the look of the balcony.

“Because it’s a special project connected with Los Angeles (based on the classic 1950 movie), it would have been wonderful to open there first,” Lloyd Webber told The Times in London. “But we found that the Shubert, the theater we wanted to go into, has a design problem. At one point there’s a huge gap in the building; it’s like playing to two different theaters. The Shuberts said they would like to have ‘Sunset Boulevard,’ so I said to them, look, is this not the moment for you to address the problem of the theater?”

It’s a problem that only Lloyd Webber has perceived, responded Shubert Organization President Bernard B. Jacobs. “He believes that the crossover (aisle that divides the front and rear of) the balcony tends to divide the audience. He believes you should have a uniform line of seats, which requires changing the grade of the balcony”--and “a lot of money.”

However, added Jacobs, “when you are Andrew Lloyd Webber, you have the power to move mountains”--or balconies. “He is the most successful composer in the history of the world.” So the Shubert Organization is “trying to put the pieces together in order to satisfy him.”

But because the renovation cannot be completed before next fall, and Lloyd Webber wanted to open the show sooner, world premiere honors will go to the London production, despite an earlier pledge by Lloyd Webber that the show would open in the United States.

Meanwhile, more details about the premiere emerged at a reception in London, held to honor the casting of Patti LuPone in the leading role of Norma Desmond.

In an attempt to defuse published reports that the original movie’s director and co-writer Billy Wilder didn’t approve of the new show, Lloyd Webber read from a letter from the veteran director, now 86, who said he intended to buy plane tickets for London to see the show.

In separate comments in Los Angeles, Wilder confirmed that he “adored” what he has seen so far of the show, based on a videotape of a workshop performance. “I was crazy about it, I was delirious with happiness,” he said. Published reports to the contrary were “absolutely idiotic.” He noted that the book for the musical “left the (film) script (co-written by Wilder with Charles Brackett and D.M. Marshman Jr.) untouched, and I was very proud of that.”

LuPone has a nine-month commitment to play Norma in London, requiring the hiring of a new Norma for Los Angeles. Lloyd Webber said he had “no idea” who would play Norma Desmond in Los Angeles. But Meryl Streep has reportedly shown interest. According to sources close to the production and to Streep, the star attended a workshop performance of “Sunset Boulevard,” featuring LuPone, at Lloyd Webber’s country mansion Sydmonton in September, but she wasn’t interested in performing the role in London.

Lloyd Webber said he wanted LuPone “to have the world premiere, wherever it was” and that “there had never been any contest” in terms of choosing LuPone. “She knocked them dead at Sydmonton. We’d have to go a long way to find anyone better.”

He expressed a similar devotion to the idea of staging the American premiere in Los Angeles. “Whatever happens, the show should open in America in Los Angeles first,” he said, noting that his “Phantom of the Opera” is still flourishing after four years at the Ahmanson Theatre. “It has become a theater town. We would have thought of the Ahmanson first (for the “Sunset Boulevard” premiere), but for the fact that ‘Phantom’ is still there.”

However, the importance of L.A. was disputed in a separate remark by LuPone: “Me and (co-star) Kevin (Anderson) are disappointed we’re not doing Los Angeles. But as far as Andrew and (director) Trevor (Nunn) are concerned, London and New York are the important openings.”

“For this American actor,” added LuPone, “I consider myself incredibly fortunate to play in London.”

Best known to Americans for starring in Lloyd Webber’s musical “Evita” and for her work on ABC’s “Life Goes On,” LuPone professed herself delighted at the chance to portray Norma, adding: “I think it’s possibly Andrew’s most original score since ‘Evita.’ ”

LuPone, 43, will end her stint on “Life Goes On” in February. “TV has been boring at best,” she noted. “There’s no energy, it’s lackadaisical, it’s hurry up and wait. But there’s something relentless about the stage. I’m happy to be back.” After February, she will return to her home in rural Connecticut, where she lives with her husband and baby son to get her voice into what she calls “fight training mode” for the June opening.

Free-lance writer Gritten reported from London; Times staff writer Shirley reported from Los Angeles.