Henri Dutilleux, 97, a composer whose modest output belied his huge impact on listeners and musicians alike, died Wednesday in Paris, European news services reported.

Mr. Dutilleux, born in Angers and trained at the Paris Conservatory, maintained a compositional link with Debussy and Ravel while taking their economy and elegance to greater levels of complexity and dissonance.

Conductor Charles Dutoit, a Dutilleux champion who led several notable premieres, said that his death, though expected, was a major loss.

"He was a humble, intellectual musician," said Dutoit in a call from Singapore, categorizing Mr. Dutilleux as one of the most important composers of the second half of the 20th century. "His way of writing music was like Ravel's - the orchestrations so precise, everything the result of deep thinking. The sad part is that he composed very little, in fact. He would tell me how slowly he was composing. Picasso could complete a picture in a day, but it took Dutilleux several years to come up with a new piece."

Though based in France, he received major commissions from U.S. ensembles such as the Boston Symphony Orchestra, which premiered his Symphony No. 2 in 1959. Several works have become part of the standard orchestral repertoire: Timbres, espace, mouvement; Métaboles; and the cello concerto Tout un monde lontain.

While other mid-20th-century composers grew more academic, or, in some cases, looked back longingly to traditional tonality, Mr. Dutilleux went his own way - intellectually rigorous, deploying aspects of impressionism, and, though not programmatic, often expressive of the human condition.

"He had this incredible gift of writing for orchestra and producing the sound he felt," said Dutoit. "I am sure he was feeling exactly the way he was writing, because otherwise you cannot write music so precisely. He was a master."