Everything Everywhere, the operator of the Orange and T-Mobile brands, launched a high-profile campaign on 30 April to push for the early adoption of 4G mobile internet in the UK.
The campaign was criticised by competitors, which said Everything Everywhere wanted the UK to adopt 4G before its rivals were ready.
Media reports identified City agency Brunswick and GolinHarris as being behind the campaign.
Ben Padman, head of group media relations at Vodafone, said: 'While GolinHarris has done some good work for us in Asia, we have now terminated our relationship with them.'
GolinHarris declined to comment.