Slater Investments has taken its stake in 21st Century Technology to more than 10%. The latest share purchase takes the Slater Investments shareholding to 10.4%. 21st Technology's main product is EcoManager, which is an on-board monitoring system that helps to reduce fuel costs for bus operators and other fleet managers. Drivers are given information about how they are driving and, thereby, how to improve their fuel economy. The company also supplies onboard CCTV equipment for buses. House broker Daniel Stewart forecasts an improvement in pre-tax profit from £0.7m to £0.8m in 2010 - mainly due to a lower interest charge. A profit of £1.1m is forecast for 2011. Peter Gyllenhammar owns 29.5% of 21st Century.