Its new digital sales operation, FRSD, will offer advertisers the opportunity to buy space on the websites of the 132 radio stations in its portfolio.
The sales house, a joint venture between UTV and The Local Radio Company, has signed ad serving company Atlas to provide the technology for the service.
Neil Webster, managing director of First Radio Sales, said the company had developed to accommodate demand.
"Advertising agencies have been approaching us for some time to add online campaigns to sit alongside their broadcast campaigns," he said.
"The addition of FRSD is a natural extension to our broadcast business and provides a good link-up for both our stakeholders and advertisers."
By widening its remit, the company will be able to sell broader packages to advertisers offering national radio and web coverage via their entire portfolio of stations and sites.
FRSD, which is set to launch in the summer following Beta testing in June, will enable advertisers to target website visitors by individual site, TV region and package - such as geographically, by group or audience demographic.
It will eventually be rolled out to encompass clients outside radio that have a large localised web presence, such as regional news-papers.
Investment will come from The Local Radio Company and UTV, but the figure has yet to be announced.
First Radio currently employs 22 people in London, Manchester and Birmingham and is preparing to make a series of signings to work on the new service.
First Radio Sales, which had a client turnover of about £14m in 2006/7, provides national sales services to stations across the UK, working with groups including CN, UKRD, Lincs FM and Town and Country Broadcasting.
Its client stations reach 4.5 million listeners every week and total 45 million listening hours.
United Kingdom
First Radio Sales broadens remit with digital set-up
LONDON - National sales agency First Radio Sales is branching out into digital - and eventually regional press - sales.