The Formula 1 team have confirmed that Boullier has left his position amid reports that he is to join McLaren for the 2014 campaign.
Lopez said: "Lotus F1 Team has never stood still and we head into what promises to be an exciting 2014 season with an innovative new car, new partners and a new management structure at Enstone. Great things have been achieved over the past years and we need to continue this momentum.
"With this in mind, we are proud to announce that we have concluded an agreement with YotaPhone and its shareholders. YotaPhone shareholders will become important partners to Genii and YotaPhone a sponsor to the Lotus F1 team this year. We thank Eric for all his hard work over the past four years and we are confident we can continue to fight as one of the top teams in Formula 1 over the seasons ahead."