NEW YORK — Seeing little hope for improvement in the rayon market, Lenzing AG on Monday sold a 61 percent stake in its U.S. operations to a group comprising some of the unit’s management and outside financial investors.

Terms of the transaction were not disclosed. The company said it was keeping its 39 percent stake in the company to maintain access to the U.S. nonwovens market.

The Austrian parent company said it decided to sell the stake in its rayon-producing Lenzing Fibers Corp. unit due to continued tough business conditions. Lenzing AG said its rayon sales didn’t improve even after its only U.S. rival, Acordis Cellulosic Fibers, which also makes Tencel lyocell, closed its Mobile, Ala., rayon plant in April.

Lenzing AG said it would continue to provide research and development and other support to the Charlotte, N.C.-based U.S. unit, which has its plant in Lowland, Tenn.