MIG's 4th Screen will now become 3 UK's sales partner, with Mobix providing the technology platform on which the videos will be delivered.
News, weather and film reviews will be available later in the year, while comedy and music content will be added at a later date. The services, which will either be free or cost a minimal amount - up to 50p - will sit alongside 3's current offerings of mobile games and music downloads.
Mark Slade, managing director 4th Screen Advertising, said the 3 UK portal is a prime piece of advertising real estate. Slade added that the pre-roll advertising will be highly targeted, allowing campaigns to be more effective and reach the right customer at a time that suits.