The Daily Mail and Evening Standard publisher is the second national press group to begin using AdFast, after the Financial Times took it on last summer.
AdFast general manager Rob Fogwill said he was "hopeful" that other national newspaper groups would follow Associated's lead.
"It has always been our hope that AdFast will become a portal through which files can be sent to all UK newspaper titles, and this is a major step forward toward this goal," he said.
The launch of Adfast at Associated, which also publishes Metro, has come in the same week that the group became the first in the UK to implement VCSP, a contract soft-proofing package from Vio.