The closure of various polluting viscose fiber plants in China helped to raise viscose fiber prices and contributed to lift the demand for Lenzing's wood-based Modal and Tencel fibers in the first half of this year. Combined with positive currency effects and a better product mix, this led the Austrian company to post a 6.2 percent sales increase to €955.4 million for the quarter, and to improve margins. Operating margins grew to 13.2 percent of sales before amortization (Ebitda) from 10.2 percent in the year-ago period. After amortization, the operating margin (Ebit) went up to 6.3 percent from 3.6 percent.