Reuters-backed online information service Multex Investor Europe has hired Masius as its first ad agency.
Masius beat three unnamed brand response agencies for the work, which is worth between pounds 5m and pounds 10m.
The web site, which provides broker research to private investors, launched in the UK in September and in Germany just before Christmas. It is set to roll out across Europe.
Media will be handled by MediaVest, and Masius will team up with D'Arcy partner agencies in Germany and France for local drives.
The site offers research from about 40 providers, such as Deutsche Bank.
It is a joint venture between Reuters and US company Multex.
Multex Investor Europe marketing director Peter Crawshaw said the direct response campaign will use press ads, e-mails and inserts, and may extend to TV.
He added that the challenge will be targeting. 'Under 10% of the population will want to use us,' he said.
The campaign will break in the UK at the end of February. The site can be found at www.multexinvestor.co.uk.