Bayer AG, Europe's second- biggest chemical maker, said first-half sales in China increased 22 percent and its workforce jumped by almost a third this year on rising demand for chemicals and plastics, Bloomberg reported. Bayer MaterialScience AG contributed the bulk of the gains, its sales rising 18 percent from a year earlier to 673 million US dollars and expected to exceed 1.25 billion US dollars for the first time in 2006, said Bloomberg, quoted Chief Executive Officer Werner Wenning as saying. Bayer will spend 1.8 billion US dollars by 2009, its largest overseas investment, building plants at Caojing to tap demand for chemical products used to make cars and insulate buildings. Bayer's China workforce has increased to 4,900 from 3,700 this year, reflecting the Leverkusen, Germany-based company's expansion in the world's fastest-growing major economy. ``Further increases are planned for the coming months and years, in line with China's socio-economic development,'' Wenning told reporters at a ceremony to mark the opening of three MaterialScience plants at Caojing. MaterialScience has ``a mid-term'' target of sourcing more than 25 percent of its sales in the Asia-Pacific region, where demand is rising by about 20 percent a year, led by China, Wenning said. The company, one of the major chemical investors in China, had sales of 1.62 billion US dollars in Greater China last year.