Manning, 47, is to take over Omnicom's UK umbrella group and encourage greater collaboration between the two OMD British operations - Manning Gottlieb OMD and OMD UK.
The two agencies operate with separate identities and cultures within the domestic market, but report to Colin Gottlieb, the chief executive of OMD Europe, as a single group entity.
Manning is expected to assemble a group management team to oversee OMD's UK operations. The two agencies co-operate with negotiations and combine their research, online and econometrics resources but are expected to forge closer links. This change would mirror the structure found in OMD's other European operations.
The move is a continuation of a trend seeing agencies attempting to leverage their UK group capabilities and follows the creation of Interpublic's Magna and WPP's Group M umbrella organisations.
Taylor took the enlarged role as the head of the OMD UK Group two years ago. He has been suffering from a long illness but is still expected to take a senior management role within the agency.
Although a late entrant to the media market, Omnicom's OMD network has had some recent successes. Last year, it won the $1.2 billion McDonald's global account, the $60 million global Allianz business and the £25 million pan-European assignment for easyJet.