Public transport CCTV company 21st Century Technology recorded a 39% growth in sales in the first half, helped by a significant contract with Swedish bus operator Keolis Sverige.Revenue for the six months ended 30 June jumped from £5.63m to £7.83m, while pre-tax profit surged 76% from £0.3m to £0.53m. Basic and diluted earnings per share rose from 0.37p to 0.57p.In January, the firm was awarded two contracts with Keolis for a total value of £7.2m, £6.4m of which is expected to be delivered in the full year. As at the end of the half year, £4.72 was invoiced in respect of these.The group also provides mobile CCTV to bus operator giants Arriva UK Bus, Go-Ahead and FirstGroup UK Bus. The latter was added to the client list at the start of 2010 and 21st Century has seen sales almost double to £1.00m, from £0.51m in the first half of the previous year."We have delivered another strong performance for the period on the back of new contracts won in mainland Europe and improved sales in the UK on certain contracts," said chairman Jan Holmstrom.The company said it is considering paying a full-year dividend.Shares were flat at 16.62p on Tuesday.BC