Stoke-on-Trent based ceramics maker Portmeirion almost doubled profit during the first half of the year and said it remains confident despite an expected tough climate in the second half.Profit before tax increased to £1m for the six months to 30 June 2010 from £532,000 the same time a year earlier. Revenue for the period rose to £21.1m from £17m before helped by its recent acquisitions. Commenting on the results, chairman Dick Steele said, "This is a strong set of results, achieved despite difficult worldwide economic conditions, and demonstrates the strength of our brands."He added, "Last year's acquisition of the Spode and Royal Worcester brands has accelerated our growth and we continue to invest in these brands. The performance of the first six months lays good foundations for the full year, and we are confident of the group's prospects."The board is recommending a dividend of 3.9p per share, an increase of 10% on the interim dividend paid in 2009.