21st Century Technology has acquired RSL Group, a developer and supplier of public information systems for bus travel, for £1.3m.The provider of vehicle electronics for passenger cars and motorcycles said it will pay £1.1m in cash and the remaining £0.2m loan note.The company reckons the purchase will help the business to diversify earnings and add software capability.RSL comprises three companies under common control: Region Consultants, Region Services and RSL Cityspace. It reported sales of £4m and operating profits of £0.4m in the year ended 30 June 2014.Chief executive Russ Singleton said: "This acquisition combines some important capabilities to develop new, class-leading products and services to help us grow our business and deliver enhanced value for money solutions to customers through our economies of scale."