Although its contract with Ferrari does not expire until the end of 2006, the mobile phone operator is believed to be considering ending the tie early. It follows the team's underperformance this season.
If Vodafone does end the deal it is expected to switch its investment to another team.
A Vodafone spokeswoman confirmed the sponsorship was under review but denied a decision had been made or that it was pulling out of F1. An announcement is expected imminently.