However, its renewal of its diary system of measurement until December 2005 drew scathing criticism from Rajar's main opponent, Kelvin MacKenzie, the chairman and chief executive of The Wireless Group.
MacKenzie said: "Rajar claims there is a 'very real possibility' of introducing technology-based audience research and at the same time announces an extension of paper diaries that will take us until January 2006 at least."
The talkSPORT owner said he still intended to seek damages from Rajar for failing to introduce new technology, claiming that it does not accurately reflect the audience of his stations.
Rajar defended its decision to extend the diary-based contract with Ipsos-RSL by a year, arguing that this would avoid the need to put a new long-term contract in place.
Its trials of the Arbitron and Radiocontrol measurement systems will start in July with results in by the end of year. This follows a 15-month trial run by Rajar that ended inconclusively earlier this year.
The research body also announced that it would increase the sample of 15- to 34-year-old males used in its research to reflect changing census trends.
Sally de la Bedoyere, Rajar's managing director, said: "Plans for 2004 will ensure that we shall continue to produce the highest standard of research on behalf of the radio industry."