Willam Christensen (August 27, 1902- October 14, 2001) was one of the three Christensen brothers who, as choreographers, teachers and directors, helped ballet flourish in this country. He and his brothers — Lew, who died in 1984, and Harold, who died in 1989 — worked primarily in the West. But their influence was felt nationwide.

Wherever Mr. Christensen settled, a ballet company would seem to spring up. When he started teaching at his uncle’s dancing school in Portland in 1932, he soon organized a company of its students. The group disbanded after he was hired as a leading dancer of the San Francisco Opera Ballet in 1937. The next year, he took over that company as director and it survives today as the San Francisco Ballet, one of America’s major troupes.

Leaving the San Francisco company and its school in the hands of Lew and Harold, Mr. Christensen moved to Salt Lake City in 1951 because he thought its climate might be beneficial for his ailing wife, Mignon. He started teaching ballet at the University of Utah and out of these classes grew a whole university ballet department and, then, a student group which became professional in 1963 and which has been known as Ballet West since 1968. He retired as director in 1978, after which he ran his own Christensen Ballet Academy.

In San Francisco Mr. Christensen staged the first complete American productions of ”Coppélia” (1939), ”Swan Lake” (1940) and ”The Nutcracker” (1944), basing his versions on historical research and the reminiscences of older dancers who had performed those works in Europe. Mr. Christensen’s ”Nutcracker,” created a decade before George Balanchine’s production, helped establish the tradition of presenting this Tchaikovsky ballet as a Christmas holiday treat.

Mr. Christensen’s original works — including the lighthearted ”Winter Carnival” and ”Nothin’ Doin’ Bar,” a Prohibition farce — tended to be vigorous, accessible pieces, for he believed in ballet as a form of theatrical entertainment capable of pleasing everyone.

William Farr Christensen was born in 1902 in Brigham City, Utah, a member of a Danish Mormon family that had settled in America. All his life, he insisted that ballet was not an inherently foreign art.

Mr. Christensen’s grandfather taught folk and social dancing in Brigham City. His father and uncles were also teachers of social dancing who, over the years, opened schools throughout the Northwest. At teachers’ conventions the Christensens were introduced to ballet, and the three brothers received sound classical training from various teachers.

During the late 20’s and early 30’s they toured as a vaudeville act. But, thanks in part to their own pioneering efforts as teachers and choreographers, ballet became increasingly popular and the Christensens were able to leave the vaudeville stage.

His students over the years included Janet Reed, Scott Douglas, Onna White, Jocelyn Vollmar, Kent Stowell, Bart Cook and Michael Smuin, all of whom had notable careers in ballet and musical theater in the East as well as the West.

The Christensen brothers received the Dance Magazine Award in 1973 and the Capezio Dance Award in 1984.