Victrex posted a 10% rise in pretax profit to £53.9m for the first half of this year, on revenue of £130.3m, up from £120m in 2014, as a strong performance in its polymer solutions offset lower sales to its oil and gas customers.The company, which specialises in high performance polymer products, raised its interim dividend to 11.73p from 11.39p a year earlier.Looking ahead, the company's chief executive David Hummel said : "For the second half year, we are mindful of the tougher comparatives and the ongoing caution in the Oil and Gas market.""Foreign currency remains a considerable headwind although we still expect to fully overcome the impact through our positive growth momentum. Consequently, Victrex continues to be well positioned for profit progress over the full year."