India, Aug. 13 -- Japan's Kuraray Co Ltd reported a 42 percent plunge in first-half operating profit as its rubber and speciality chemicals business grappled with weakened European demand and inventory valuation losses, prompting the company to slash its full-year earnings forecast.

The Okayama-based manufacturer, known for its synthetic rubber and speciality polymers used in automotive and industrial applications, posted operating income of 26.3 billion yen for the six months ended June 30, down from 45.5 billion yen a year earlier.

Net sales slipped 2.7 percent to 400.0 billion yen, with the company's flagship vinyl acetate segment - which includes rubber-related products - bearing the brunt of the downturn as volumes declined across ...