China's largest producer of polyester products, Sinopec Yizheng Chemical Fibre Co, on Monday said it swung to a first quarter profit as increased sales and prices offset volatile raw material costs. The firm, which recently announced plans to axe 3,000 jobs by 2005, posted an unaudited net profit of 63 million yuan ($7.6 million) versus a year-ago loss of 55.5 million yuan $6.7m), with sales up 6.4 per cent year-on-year.