Foster is privately funding the new agency. Teqtonic will offer clients various online media planning and buying services, as well as eCRM and data analytics skills.
His plan is to bring direct marketing and digital skills under one roof, something he believes other agencies are not currently delivering.
Foster said: "Many traditional direct response agencies have not fully embraced the world of digital media and digital agencies don't know enough about direct marketing. Digital marketing should not remain as a division or group within direct response agencies."
The agency has yet to secure any clients, and Foster is not planning to staff up until the agency has briefs to work on.
Foster was hired by PHD in 2002 to set up its direct response unit, PHD Confidential. He left the agency in September 2006 with hopes of setting up his own business.
After leaving, Foster was linked to a Mother-backed start-up, alongside Mike Cornwell and Richard Madden. However, these plans never came to fruition.
Foster added: "You can find yourself being pulled in a lot of directions. I don't want a repeat of last year, when I was a cog in something much bigger, I'd much rather do it my way."
His career includes stints at Caci, Channel 4 and O&M Direct. He has also been a managing partner at MindShare Direct, the communications planning director at Initiative and the European interactive media director at FCBi.