J Walter Thompson digital guru Tim Hayward has quit the agency and is understood to be in talks with TBWA/London.
Hayward, who helped set up JWT's digital@jwt arm, is thought to be planning a digital operation at TBWA.
The agency refused to comment on the reports but admitted it was in talks with several people about building up its digital capabilities.
Chief operating officer Neil Christie said: "We already have a small digital operation which we are looking to expand in the context of the need to offer a total communications package."
JWT played down Hayward's departure, claiming his role within the agency was finished. Digital@jwt's managing director Jeremy Davies said his skills lay in building growth and accelerating change.
"We knew from the start that responsibility for the continued development and profitable running of the business beyond initial growth phase would be handed off to different members of the team," he said.
There are no plans to replace Hayward at JWT.