The campaign, South West Stories, features businesses in the region, including Intel and Ecotricity, explaining the business benefits of their location.
It will consist of display ads from Intel, with a 30-second banner ad that will appear in the business sections of the Financial Times, The Times and The Daily Telegraph websites.
Times Online will also run a special report that will communicate the advantages to business of the South West region with ads around the site.
Space managing partner David Atkinson said that targeting the readers of online business sections, in conjunction with other integrated marketing activity, would drive awareness of the business benefits of the region among senior business decision-makers.
Other campaigns by Space include Nivea, VisitBritain and a Eurostar campaign that exploited its partnership with The Da Vinci Code film.
The South West of England Regional Development Agency was set up by the Government in 1999 in order to give more emphasis to regional development in England.
It is charged with ensuring the long-term economic success of the region.