China´s man-made fiber sector is already the largest in the world by a wide margin; but despite this achievement, it continues to expand. April MMF output reached 1.964 million tons, which represented a 3.17 percent increase from March and 18.86 percent year-on-year growth. The capacity growth in polyester has continued to pressure profit margins for the sector; however the increase in output is being led by viscose fiber, which increased 29 percent in first quarter 2007.