Rolling Stones Cancel Australian Concert After L'Wren Scott Death

* Mick Jagger described as "devastated" after death

* Medical examination to determine cause of death set

* Scott's company had been making financial losses (Adds medical examiner comment, reaction)

By Lincoln Feast and Patricia Reaney

SYDNEY/NEW YORK, March 18 (Reuters) - The Rolling Stones cancelled a concert in Australia, leaving their 'Down Under' tour in limbo on Tuesday, after lead singer Mick Jagger's girlfriend L'Wren Scott was found dead in her Manhattan apartment.

Scott, a 49-year-old fashion designer and former model, was found hanging from a scarf on Monday, police said, adding they were treating her death as a suicide..

A medical examination to determine the exact cause of death was set for Tuesday.

"The examination is scheduled for today and it may or may not yield a manner of death by later today," said Julie Bolcer, a spokeswoman for the Office of Chief Medical Examiner.

Jagger, 70, said through a spokesperson he was "completely shocked and devastated".

The news of Scott's death stunned friends, clients and fellow designers. Hollywood star Nicole Kidman, a friend of 25 years, was "heartbroken and in shock right now and unable to say anything," her spokeswoman said.

The Rolling Stones had been due to kick off a six-concert Australia and New Zealand leg of their world tour on Wednesday in Perth in western Australia. But the group's Australian publicist on Tuesday said the concert would not be going ahead.

Frontier Touring declined to comment on whether Jagger and other band members were planning to return to the United States or whether other Australian concerts would be affected.

"No further information is available at this time, ticket holders are asked to hold on to their tickets until a further update is available," Frontier Touring said in a statement on Tuesday.

Jagger and bandmates Ronnie Wood, Keith Richards and Charlie Watts landed in Perth on Monday in their private jet, emblazoned with the famous tongue and lips logo. The aircraft remained on the tarmac.

Jagger's daughter, Georgia May Jagger, also cancelled a planned appearance at Australia's Melbourne Fashion Festival this week, according to local design house Camilla, for whom she was scheduled to model.

"TOTAL PERFECTIONIST"

Scott and Jagger had been dating since 2001 and were often seen at celebrity events, with the 6-foot, 3-inch (1.91-metre) tall former model towering over her rock-star boyfriend.

Scott became one of New York's most famous designers over the last decade and was best known for her slim-fitting, sexy dresses favoured by Hollywood stars.

Pop singer Madonna in a statement described Scott's death as "horrible and tragic." Supermodel Naomi Campbell, who knew Scott for many years, said she was the "epitome of elegance and femininity."

Anna Wintour, Vogue editor-in-chief, also expressed her sadness.

"L'Wren was a total perfectionist, someone who absolutely embodied everything her marvellous clothes stood for: strength of character combined with a confident and powerful style," Wintour wrote on Vogue.com.

Although Kidman, Amy Adams and Penelope Cruz were pictured in Scott's creations on the red carpet, her company was making losses. Accounts filed with Britain's Companies House last October show that Scott's LS Fashion Ltd ran a loss of 4.3 million euros ($5.99 million) in 2012, up from 3.0 million euros the year before.

A publicist for Jagger said a New York Post story about a split between the two was "100 percent untrue" and "a horrible and inaccurate piece of gossip during this very tragic time for Mick."

A single bouquet of yellow daffodils was placed in front of the glass-fronted, high-rise building in her upscale Chelsea neighborhood after Scott's body was found on Monday.

Musician and fashion friends of the couple took to Twitter to express their grief.

"Devastated to have lost my friend," tweeted rocker Bryan Adams, who has photographed Scott. "Rest in peace my dear I'm gonna miss you. Condolences to all that were close to her."

American fashion designer Marc Jacobs said: "You'll forever be missed."

Banana Republic, which had collaborated with Scott on a small holiday collection, said her death was terrible news.

"We are stunned and saddened to learn of the loss of L'Wren Scott. Our hearts and prayers go out to her friends and family," it said.

Scott, born Luann Bambrough, was raised in Utah by adoptive parents. She started her career as a model in Paris before becoming a stylist and designer.

Her love of fashion began when she made her own clothes as a teenager, according to her website. After moving to Los Angeles, she worked as a stylist and designed privately before creating her own collection.

($1 = 0.7180 Euros) (Additional reporting by Victoria Cavaliere, Edith Honan, Piya Sinha Roy, and Belinda Goldsmith; Editing by Marguerita Choy)