By James Mackenzie

PARIS (Reuters) - France said farewell to fashion designer Yves Saint Laurent at a funeral on Thursday attended by supermodels, film stars and President Nicolas Sarkozy.

Office workers and residents of nearby buildings leaned out of their windows as police held crowds back near the Paris church of Saint Roch where the ceremony was held.

Actress Catherine Deneuve, whose aura of refined elegance was most closely associated with the designer, read a poem by Walt Whitman, followed by a speech from Saint Laurent's long-time partner and business associate Pierre Berge.

"You could have slid into fashions at times, but instead you remained faithful to your own style, and you were quite right, for that style is now everywhere, perhaps not on fashion catwalks but in the streets of the whole world," Berge said.

Although Saint Laurent himself famously hated his own time as a conscript in the French army, his coffin was greeted by an armed honor guard, whose stiff military bearing contrasted strangely with the elegant mourners mingling after the service.

Sarkozy sat in the front row of the church alongside his wife Carla, a former supermodel who used to strut the catwalk at Saint Laurent's glamorous shows.

Hailed as one of the great couturiers of the 20th century, Saint Laurent was part of a distinguished line of French designers from Coco Chanel to Christian Dior who consolidated the reputation of Paris as the fashion capital of the world.

A shy and reclusive figure in his later years with few close friends, his rank in the fashion world could nonetheless be gauged from the array of celebrities at Saint Roch, a church traditionally associated with artists and musicians.

Screen legend Jeanne Moreau joined the mourners, along with some of the models he dressed, including Claudia Schiffer and Laetitia Casta, and leading designers Christian Lacroix, John Galliano, Vivienne Westwood and Jean-Paul Gaultier.

Saint Laurent's body is to be cremated and the ashes spread in the garden of his villa in the Moroccan city of Marrakesh.

The oldest child of a rich French industrialist, Saint Laurent was born and grew up in Algeria, then a French colony, and showed an early talent for design, making clothes for his younger sisters' dolls.

After moving to Paris at the age of 17, he was hired by Christian Dior and soon became chief designer, producing acclaimed collections under the Dior label before striking out under his own name in 1962.

With Berge taking care of the management side, Saint Laurent built up the YSL brand into one of the world's most widely recognized fashion labels with hallmark designs like his women's tuxedo and trouser suits.

However he struggled with alcohol and drug problems as well as ill health and he became disillusioned with the fashion scene after he retired from designing in 2002.

(Additional reporting by Elizabeth Pineau)

(Editing by Crispian Balmer)